The U.S. is taking recent signaling from the Kremlin very seriously, and does not consider the matter a bluff, a senior U.S. defense official told Fox News.
Russia already has about 100,000 troops stationed along its border with Ukraine, the defense official said.
"We’ve been aware of Russia’s actions for a long time and my expectation is we’re gonna have a long discussion with Putin," Biden told reporters later, as he prepared to leave Washington for a weekend visit to the presidential retreat at Camp David, Maryland.
"We’ve been aware of Russia’s actions for a long time and my expectation is we’re gonna have a long discussion with Putin."
In earlier comments, Biden told reporters that his administration had new initiatives planned that were intended to deter Russian aggression.
"What I am doing is putting together what I believe to be, will be, the most comprehensive and meaningful set of initiatives to make it very, very difficult for Mr. Putin to go ahead and do what people are worried he may do," Biden said.
The planned Ukraine offensive for 2022 would involve about double the number of Russian troops that participated in a military exercise near the Ukraine border last spring.
"The plans involve extensive movement of 100 battalion tactical groups with an estimated 175,000 personnel, along with armor, artillery and equipment," a Biden administration official told Fox News.
"The plans involve extensive movement of 100 battalion tactical groups with an estimated 175,000 personnel, along with armor, artillery and equipment."
During a trip to Europe earlier this week, U.S. Secretary of State Antony Blinken said the U.S. had detected "evidence that Russia has made plans for significant aggressive moves against Ukraine."
In remarks this week, one day before meeting with his Russian counterpart, Blinken claimed Putin was preparing to have the ability to quickly invade Ukraine, whether he planned to or not – and said the U.S. needed to be ready either way.
"We must prepare for all contingencies," Blinken said.
Meanwhile, Russian Foreign Minister Sergei Lavrov, who met with Blinken in Sweden, pointed to U.S. military equipment and activity getting closer to Russia’s borders.
"The nightmare scenario of military confrontation is returning," Lavrov said, according to the Washington Post.
"The nightmare scenario of military confrontation is returning."
Lavrov’s comments echoed frequent concerns raised by Putin about U.S. and NATO activity near Russia. The Russian president has called for the West to "rule out any further eastward expansion of NATO and the deployment of weapons systems posing a threat to us in close proximity to Russia’s territory."
Biden quickly dismissed Putin’s demands when asked about them Friday, the AP reported.
"I don’t accept anyone’s red line," the president said.
"I don’t accept anyone’s red line."
In late November, NATO Secretary-General Jens Stoltenberg warned Russia that any attempt to invade Ukraine would be costly for Moscow.
"If Russia uses force against Ukraine that will have costs, that would have consequences," Stoltenberg said ahead of a meeting of NATO’s foreign ministers in Latvia, Nov. 30-Dec. 1. He did not say what those costs would be.
Biden’s personal history involving Ukraine includes his admitted role in the ouster of Ukraine Prosecutor General Viktor Shokin in 2016, when Biden was vice president.
It was former President Donald Trump’s later inquiries into Ukraine involvement by Biden and son Hunter Biden that eventually led House Democrats to impeach Trump over a phone call with a Ukraine leader. The Senate later acquitted Trump in that impeachment case and another separate impeachment that followed.
Critics say the Obama administration was caught flat-footed in 2014 when Russia invaded Ukraine soon after the conclusion of the Winter Olympics in Sochi, Russia.
Fox News' Jennifer Griffin and Patrick Ward, and The Associated Press contributed to this story.