Russia has asked China for military equipment to support its invasion of Ukraine, according to US officials, sparking concern in the White House that Beijing may undermine western efforts to help Ukrainian forces defend their country.

US officials told the Financial Times that Russia had requested military equipment and other assistance since the start of the invasion. They declined to give details about what materiel Russia had requested.

Another person familiar with the situation said the US was preparing to warn allies about the situation amid some indications that China may be preparing to help Russia. Other US officials have also said there were signs that Russia was running out of some kinds of weaponry as the war in Ukraine approaches the start of its third week.

The White House did not comment. The Chinese embassy in Washington did not respond to a request for a comment.

The revelation comes as Jake Sullivan, US national security adviser, heads to Rome for talks on Monday with Yang Jiechi, China’s top foreign policy official. People familiar with the situation said Sullivan would sternly warn China that any efforts to help Russia prosecute the invasion or avoid western sanctions would have consequences.

Before leaving Washington on Sunday, Sullivan warned China not to try to “bail out” Russia by helping Moscow to circumvent the sanctions that the US and its allies have imposed on Putin and his regime.

Recommended “We will ensure that neither China, nor anyone else, can compensate Russia for these losses,” Sullivan told NBC television on Sunday. “In terms of the specific means of doing that, again, I’m not going to lay all of that out in public, but we will