The Kremlin said on Friday that US President Joe Biden had the key to end the conflict in Ukraine by directing Kyiv, but that Washington had so far not been willing to use it. "The key to the Kyiv regime is largely in the hands of Washington," Kremlin spokesman Dmitry Peskov told reporters in a daily briefing. "Now we see that the current White House leader ... does not want to use this key. On the contrary, he chooses the path of further pumping weapons into Ukraine," he added. Moscow has often accused Washington of giving orders to Ukraine and of prolonging the conflict by supplying Kyiv with weapons. The United States says Russia has unleashed a brutal war of choice and can end it by withdrawing its troops. Tensions between the two sides have plumbed to historic lows over the past year, with the United States announcing this week that it would supply Ukraine with 31 advanced M1 Abrams tanks worth $400 million in a matter of months. Russia says any Abrams shipments would be a waste of money as they would "burn" just like other tanks in Ukraine.