Russia will "respond appropriately" if the United States deploys more troops in Eastern Europe and the Baltic countries, the Interfax news agency quoted Russian lawmaker Andrei Kartapolov as saying on Monday.
Kartapolov, who heads the Russian parliament's defense committee, spoke after the New York Times reported that US President Joe Biden was considering sending thousands of troops to NATO allies in the region amid tensions between Moscow and the West over Ukraine.
NATO allies are putting forces on standby and reinforcing NATO deployments in eastern Europe with more ships and fighter jets, Secretary-General Jens Stoltenberg said on Monday, in reaction to Russia's military build-up at Ukraine's borders.
"I welcome allies contributing additional forces to NATO," Stoltenberg said in a statement. "NATO will continue to take all necessary measures to protect and defend all allies, including by reinforcing the eastern part of the alliance."
Ukraine is not in NATO, but some of its neighbors including Poland are.