The legislation, which would allow the president to levy a 500% tariff on imports from countries that purchase Russian uranium, gas and oil, has gained momentum in the Senate as Trump has signaled he will escalate US action against Russia.

Ukraine and Russia have escalated their shadow war of espionage, sabotage, and assassinations, with both countries claiming a growing list of captured agents, intercepted plots, and cross-border attacks.

Russia and China's foreign ministers on Sunday discussed their relations with the United States and the prospects for ending the war in Ukraine, Russia's foreign ministry said in a statement.