U.S. President Joe Biden on Saturday said he had made it clear to Russian President Vladimir Putin that Russia would pay "a terrible price" and face devastating economic consequences if it invaded Ukraine.

Biden told reporters the possibility of sending U.S. ground combat troops to Ukraine in the event of a Russian invasion was "never on the table," although the United States and NATO would be required to send in more forces to eastern flank NATO countries to beef up their defenses.

"I made it absolutely clear to President Putin ... that if he moves on Ukraine, the economic consequences for his economy are going to be devastating, devastating," he said.

Biden, who spoke with Putin by telephone for two hours last week, said he told the Russian leader clearly that Russia's standing in the world would change "markedly" in the event of an incursion into Ukraine.