White House national security adviser Jake Sullivan warned Sunday that the United States is prepared to take action if Russia invades Ukraine.

During an appearance on “Face the Nation,” Sullivan revealed if Russia attacks Ukraine, the U.S. and Western allies will retaliate.

“In terms of sanctions, what we have laid out is a very clear message to the Russians, and we’ve done so in concert and in unison with our allies that if they do further invade Ukraine, there will be severe economic consequences and a price to pay,” Sullivan said.

“If it turns out that Russia is pummeling Ukraine with cyberattacks, and if that continues over the period ahead, we will work with our allies on the appropriate response.”

The Biden administration has been trying to reach a diplomatic agreement after about 100,000 Russian soldiers were reported to have gathered near the eastern border of Ukraine, sparking concerns that Russia planned to invade the country.

During a Sunday appearance on the CNN program “Fareed Zakaria GPS,” Putin’s spokesperson Dmitry Peskov blamed the U.S. military for causing Russia to send troops to the Ukraine border.

“At first, they were just words, but with the time being, we have seen the gradual invasion of NATO into Ukrainian territory, with its infrastructure, with its instructors, with supplies of defensive and offensive weapons, teaching Ukrainian military, and so on and so forth,” Peskov explained.

“And that brought us to the red line. That brought us to the situation when we — when we couldn’t tolerate it anymore.”

While Russia is against Ukraine joining NATO, Peskov hinted that a compromise could be reached.

Should Russia take aggressive military steps against Ukraine, Sullivan made it clear the U.S. will “take measures that go at their economy, that go at their strategic position in Europe, that strengthen the solidarity of NATO.”

US National Security Adviser Jake Sullivan (pictured December 7, 2021) said his visit to Israel had come at a 'critical juncture'
US National Security Adviser Jake Sullivan (pictured December 7, 2021) said his visit to Israel had come at a 'critical juncture' AFP / Nicholas Kamm