Washington, March 18 (IANS) US President Joe Biden will warn his Chinese counterpart, Xi Jinping, that he will face "costs" if Beijing rescues fellow authoritarian ally Russia from intense western sanctions aimed at punishing Moscows invasion of Ukraine, the Guardian reported. The two leaders' first phone call since a video summit in November 2021 will be a chance to air differences as the US spearheads an unprecedented pressure campaign on Russia, placing China in a geopolitical bind. It's "an opportunity for President Biden to assess where President Xi stands", White House Press Secretary Jen Psaki said of the call scheduled for Friday. The Biden-Xi call comes after Moscow was accused by the UK, the US, France, Albania, Ireland and Norway of war crimes, and Paris claimed Russian President Vladimir Putin was only pretending to be interested in negotiating a peace deal. US Secretary of State, Antony Blinken, who has warned repeatedly that Putin will turn to the use of chemical weapons, said the Biden administration was gathering evidence of war crimes and appeared to dismiss hopes of a resolution through diplomacy. Amid signs of a faltering Russian invasion, the Pentagon reportedly assessed that Putin may resort to threats to use nuclear weapons as sanctions and setbacks on the ground "slowly weaken Russian conventional strength", the Guardian reported.