U.S. President Joe Biden and Russian President Vladimir Putin bolstered their respective alliances with NATO and China ahead of the first anniversary of Moscow's invasion of Ukraine.
Global tensions between superpowers were highlighted on a day of diplomacy in Warsaw and Moscow on Wednesday. Biden promised that the United States "will defend literally every inch of NATO," the military alliance that includes some Eastern European countries bordering Russia.
Putin said Chinese leader Xi Jinping would visit Russia, saying relations had reached "new frontiers." Washington is concerned Beijing could provide material support for Moscow's war in Ukraine, which began on Feb. 24 last year and has become the biggest land conflict in Europe since World War II.