U.S. officials pledged to crack down on shipments to Russia that can be used for both civilian and military purposes, but that has proved hard to police.WASHINGTON — President Biden and his top officials vowed this week to introduce additional sanctions aimed at impeding Russia’s war efforts against Ukraine. But the administration’s focus is increasingly shifting to the role that China has played in supplying Russia with goods that have both civilian and military uses.As one of the world’s biggest manufacturers of products like electronics, drones and vehicle parts, China has proved to be a particularly crucial economic partner for Russia.Beijing has remained officially unaligned in the war. Yet China, along with countries like Turkey and some former Soviet republics, has stepped in to supply Russia with large volumes of products that either civilians or armed forces could use, including raw materials, smartphones, vehicles and computer chips, trade data shows.Administration officials are now expressing concern that China could further aid Russia’s incursion by providing Moscow with lethal weapons. While there is no clear evidence that China has given weapons and ammunition to Russia, Secretary of State Antony J. Blinken warned in recent days that China may be preparing to do so.President Biden, speaking in Kyiv on Monday, said the United States and its partners would announce new measures targeting sanctions evasion this week. He did not specify whether those actions would be directed at Moscow or its trading partners.“Together we have made sure that Russia is paying the price for its abuses,” he said the next day in Warsaw.And in a speech on Tuesday at the Council on Foreign Relations, Wally Adeyemo, the deputy Treasury secretary, said the United States would be working “to identify and shut down the specific channels through which Russia attempts to equip and fund its military.”“Our counterevasion efforts will deny Russia access to the dual-use goods being used for the war and cut off these repurposed manufacturing facilities from the inputs needed to fill Russia’s production gaps,” he said.The comments came on the same day that Wang Yi, China’s top diplomat, visited Moscow.The actions that the United States has taken against Russia in partnership with more than 30 countries constitute the broadest set of sanctions and export controls ever imposed against a major economy. But this regime still has its limits.One year into the war, the Russian economy is stagnant, but not crippled. The country has lost direct access to coveted Western consumer brands and imports of the most advanced technology, like semiconductors. But individuals and companies around the world have stepped in to provide Russia with black market versions of these same products, or cheaper alternatives made in China or other countries.Russia is unable to produce precision missiles today because the country no longer has access to leading-edge semiconductors, a U.S. official said.Maxim Shipenkov/EPA, via ShutterstockIn particular, the United States and its allies appear to have had limited success in stopping the trade of so-called dual-use technologies that can be used in both military equipment and consumer goods.The United States included many types of dual-use goods in the export controls it issued against Russia last February, because the goods can be repurposed for military uses. Aircraft parts that civilian airlines can use, for example, may be repurposed by the Russian Air Force, while semiconductors in washing machines and electronics might be used for tanks or other weaponry.The Chinese Spy Balloon ShowdownThe discovery of a Chinese surveillance balloon floating over the United States has added to the rising tensions between the two superpowers.Tensions Rise: In the aftermath of the U.S. downing of a Chinese spy balloon on Feb. 4 and three unidentified flying objects a week later, the nations have traded accusations over their spying programs.U.S.-China Meeting: Secretary of State Antony Blinken held a confrontational meeting with his Chinese counterpart on Feb. 18 in Munich, resuming diplomatic contact between Washington and Beijing.A ‘Military-Civil Fusion’: The international fracas over China’s spy balloon program has thrown a light on Beijing’s efforts to recruit commercial businesses to help strengthen the Chinese military.Unidentified Objects: As more objects were shot down after the balloon incident, experts warned that there was an “endless” array of potential targets crowding America’s skies. Here’s a look at some of them.Top U.S. officials warned their Chinese counterparts against supporting Russia’s war effort after the invasion of Ukraine last year, saying there would be firm consequences. While China has been careful not to cross that line, it has provided support for Russia in other ways, including through active trade in certain goods..css-1v2n82w{max-width:600px;width:calc(100% – 40px);margin-top:20px;margin-bottom:25px;height:auto;margin-left:auto;margin-right:auto;font-family:nyt-franklin;color:var(–color-content-secondary,#363636);}@media only screen and (max-width:480px){.css-1v2n82w{margin-left:20px;margin-right:20px;}}@media only screen and (min-width:1024px){.css-1v2n82w{width:600px;}}.css-161d8zr{width:40px;margin-bottom:18px;text-align:left;margin-left:0;color:var(–color-content-primary,#121212);border:1px solid var(–color-content-primary,#121212);}@media only screen and (max-width:480px){.css-161d8zr{width:30px;margin-bottom:15px;}}.css-tjtq43{line-height:25px;}@media only screen and (max-width:480px){.css-tjtq43{line-height:24px;}}.css-x1k33h{font-family:nyt-cheltenham;font-size:19px;font-weight:700;line-height:25px;}.css-1hvpcve{font-size:17px;font-weight:300;line-height:25px;}.css-1hvpcve em{font-style:italic;}.css-1hvpcve strong{font-weight:bold;}.css-1hvpcve a{font-weight:500;color:var(–color-content-secondary,#363636);}.css-1c013uz{margin-top:18px;margin-bottom:22px;}@media only screen and (max-width:480px){.css-1c013uz{font-size:14px;margin-top:15px;margin-bottom:20px;}}.css-1c013uz a{color:var(–color-signal-editorial,#326891);-webkit-text-decoration:underline;text-decoration:underline;font-weight:500;font-size:16px;}@media only screen and (max-width:480px){.css-1c013uz a{font-size:13px;}}.css-1c013uz a:hover{-webkit-text-decoration:none;text-decoration:none;}How Times reporters cover politics. We rely on our journalists to be independent observers. So while Times staff members may vote, they are not allowed to endorse or campaign for candidates or political causes. This includes participating in marches or rallies in support of a movement or giving money to, or raising money for, any political candidate or election cause.Learn more about our process.The United States has cracked down on some of the companies and organizations providing goods and services to Russia. In January, it imposed sanctions on a Chinese company that had provided satellite imagery to the Wagner mercenary group, which has played a large role in the battle for eastern Ukraine. In December, it added two Chinese research institutes to a list of entities that supply the Russian military, which will restrict their access to U.S. technology.But tracking by research firms shows that trade in goods that the Russian military effort can use has flourished. According to the Observatory of Economic Complexity, an online data platform, shipments from China to Russia of aluminum oxide, a metal that can be used in armored vehicles, personal protective equipment and ballistic shields, soared by more than 25 times from 2021 to 2022.Shipments of minerals and chemicals used in the production of missile casings, bullets, explosives and propellants have also increased, according to the Observatory of Economic Complexity. And China shipped $23 million worth of drones and $33 million worth of certain aircraft and spacecraft parts to Russia last year, up from zero the prior year, according to the group’s data.Data from Silverado Policy Accelerator, a Washington nonprofit, shows that Russian imports of integrated circuits, or chips, which are crucial in rebuilding tanks, aircraft, communications devices and weaponry, plummeted immediately after the invasion but crept up over the past year.In December, Russia’s imports of chips had recovered to more than two-thirds of their value last February, just before the war began, according to Silverado. China and Hong Kong, in particular, together accounted for nearly 90 percent of global chip exports to Russia by value from March to December.Shipments from China to Russia of smart cards, light-emitting diodes, polysilicon, semiconductor manufacturing equipment and other goods have also risen, the firm said.Secretary of State Antony J. Blinken said he had shared concerns with Wang Yi, China’s top diplomat, that Beijing was considering providing weapons and ammunition to aid Russia’s campaign in Ukraine.Pool photo by Stefani ReynoldsRelations between the United States and China have soured in recent weeks after the flight of a Chinese surveillance balloon across the United States early this month. But divisions over Russia are further straining geopolitical ties. A meeting between Mr. Blinken and Mr. Wang, his Chinese counterpart, on the sidelines of the Munich Security Conference on Saturday night was particularly tense.U.S. officials have been sharing information on China’s activities with allies and partners in their meetings in Munich, a person familiar with the matter said.On “Face the Nation” on Sunday, Mr. Blinken said he had shared concerns with Mr. Wang that China was considering providing weapons and ammunition to aid Russia’s campaign in Ukraine, and that such an action would have “serious consequences” for the U.S.-Chinese relationship.“To date, we have seen Chinese companies — and, of course, in China, there’s really no distinction between private companies and the state — we have seen them provide nonlethal support to Russia for use in Ukraine,” Mr. Blinken said.“The concern that we have now is, based on information we have, that they’re considering providing lethal support,” he added. “And we’ve made very clear to them that that would cause a serious problem for us and in our relationship.”U.S. officials have emphasized that China by itself is limited in its ability to supply Russia with all the goods it needs. China does not produce the most advanced types of semiconductors, for example, and restrictions imposed by the United States in October will prevent Beijing from buying some of the most advanced types of chips, and the equipment used to make them, from other parts of the world.Russia is unable to produce precision missiles today because the country no longer has access to leading-edge semiconductors made by the United States, Taiwan, South Korea and other allied sources, a senior administration official said on Monday.“While we are concerned about Russia’s deepening ties with them, Beijing cannot give the Kremlin what it does not have, because China does not produce the advanced semiconductors Russia needs,” Mr. Adeyemo said during his remarks. “And nearly 40 percent of the less advanced microchips Russia is receiving from China are defective.”But Ivan Kanapathy, a former China director for the National Security Council, said that most of what Russia needed for its weapons were less advanced chips, which are manufactured in plenty in China.“The U.S. government is very well aware that our export control system is designed in a way that really relies on a cooperative host government, which we don’t have in this case,” Mr. Kanapathy said.He added that it was “quite easy” for parties to circumvent export control through the use of front companies, or by altering the names and addresses of entities. “China is quite adept at that.” More