The United States warned Chinese firms on Thursday they would face consequences if they sought to evade any export controls imposed on Moscow in the event of Russia invading Ukraine.
US State Department spokesman Ned Price made the remark after China's Foreign Ministry said China and Russia had coordinated their positions on Ukraine during a meeting between their foreign ministers in Beijing on Thursday.
"We have an array of tools that we can deploy if we see foreign companies, including those in China, doing their best to backfill US export control actions, to evade them, to get around them," Price told a regular news briefing.
Western countries say any invasion of Ukraine by Russia would bring sanctions on Moscow and Washington has said it is prepared to impose financial sanctions as well as export-control measures.
White House national security official Peter Harrell said on Wednesday that Washington was working on the export-control measures with allies in Asia, including Japan and South Korea.
Price said Russia should know that a closer relationship with Beijing would not make up for the consequences imposed in response to an invasion.
"If Russia thinks that it will be in a position ... to mitigate some of those consequences, by a closer relationship with (China), that is not the case. It will actually make the Russian economy, in many ways, more brittle," he said.
"If you deny yourself the ability to transact with the West, to import with the West, from Europe, from the United States, you are going to significantly degrade your productive capacity and your innovative potential."
Price said US Secretary of State Antony Blinken and China's Foreign Minister Wang Yi had an extended discussion on potential implications of Russian action against Ukraine in a phone call last week.
Asked to comment on Price's remarks, Liu Pengyu, the spokesman for China's Washington embassy, replied: "We have noted relevant reports. Creating tensions does no good to easing the Ukraine crisis, but only adds more uncertainties to the region and the whole world. China is firmly opposed to this."
China's foreign ministry earlier said Wang met with Russian counterpart Sergei Lavrov and expressed "understanding and support" for Russia's position on security regarding Russia's relationship with the United States and NATO.
It said both sides coordinated their positions on regional issues of common concern, such as Ukraine, Afghanistan and the situation on the Korean Peninsula.
The UN Security Council is due to meet on Friday at the request of the United States and Britain after North Korea's launch of an intermediate-range ballistic missile last weekend.
The United States has been pushing for more international sanctions on North Korea over a recent spate of missile tests, but last month China and Russia delayed a US bid to impose UN sanctions on five North Koreans linked to their country's weapons programs.
Lavrov is in Beijing with President Vladimir Putin, who will meet Chinese President Xi Jinping on Friday before attending the opening ceremony of the Beijing Winter Olympics.
