SMIC, China’s largest chipmaker, has sent chipmaking tools to Iran’s military, ​two senior Trump administration officials said on Thursday, raising questions about Beijing’s ⁠stance in the month-old U.S.-Israeli conflict with Iran.

SMIC, which has been heavily sanctioned by the U.S. government over alleged ties to the Chinese military, began sending the tools to Iran roughly ‌a year ago and “we have no reason to believe that any of this has stopped,” one of the officials said.

The official added that the ‌collaboration “almost certainly included technical training on SMIC’s semiconductor technology.”

The officials spoke on ‌condition ⁠of anonymity in order to discuss previously undisclosed U.S. government information. They did ⁠not specify whether the tools were of U.S. origin, which would likely make shipment to Iran a violation of U.S. sanctions.

SMIC, the Chinese Embassy in Washington, and a spokesperson for the Iranian mission to ​the United Nations did not immediately ‌respond to requests for comment.

The Chinese government maintains that it carries out normal commercial trade with Iran. SMIC, which was added to a trade blacklist in 2020 that restricts its access to U.S. exports, has denied allegations that it ‌has ties to the Chinese military-industrial complex.

China has not publicly taken a side ​in the West Asia conflict. Chinese Foreign Minister Wang Yi this week called on the parties to seize all opportunities to start ⁠peace talks as soon as possible.

The allegations threaten to heighten tensions between Washington and Beijing as the U.S. wages war against Tehran and as it has sought to choke ‌off China’s advanced chip industry.

Reuters reported last month that Iran was close to a deal with China on the purchase of anti-ship cruise missiles, just as the United States deployed a vast naval force near the Iranian coast ahead of strikes on the Islamic Republic.

It was not immediately clear what, if any, role the chipmaking tools have played in Iran’s response to the war, which was launched by ‌the U.S. and Israel on February 28 and has roiled financial markets, triggered a surge in ​oil prices and fuelled global inflation fears.

One of the officials said the tools have been provided to Iran’s “military industrial complex” and could be used ⁠for any electronics that require chips.

Washington has sought to curtail China’s ability to make advanced ⁠semiconductors through sanctions on SMIC and other Chinese chipmakers, aiming to limit their access to advanced chipmaking equipment from top U.S. suppliers such as Lam Research, ‌KLA and Applied Materials. The Biden administration tightened restrictions on SMIC in 2024 by cutting off its most advanced factory from more U.S. imports after it ​produced a sophisticated chip for Huawei’s Mate 60 Pro phone, Reuters reported.