"If war breaks out it will be a huge human cost to Ukraine but, based on our preparations, we believe it will also come at a strategic expense to Russia," Sullivan stated.
Sullivan didn't address reports that the White House had briefed lawmakers about a possible Russian invasion of Kyiv. He did however make appearances on a trio Sunday talk shows.
An exercise of Russia's nuclear strategic forces, which is usually held every fall, was rescheduled to take place from mid-February through March. This coincides with the window that U.S. officials consider most likely to invade.
In recent days, the administration has intensified warnings that Russia is increasingly intent on invading Ukrainian territory.
Biden administration officials stated last week that intelligence findings had shown that Russia had fabricated an elaborate plot to attack Ukrainian forces. This could be used by Russia as a pretext for taking military action against its neighbor.
John Kirby, a Pentagon spokesperson, said that the plan included the production of a graphic propaganda film that would show explosions and use corpses as well as actors portraying grieving mourners.
Sullivan stated that it could happen tomorrow, or it could take several weeks. Putin has "put himself in a position to be able act aggressively against Ukraine at anytime now" by deploying military forces, Sullivan said.
Sullivan stated that the administration hoped that the Russians would de-escalate the crisis through diplomacy.
Sullivan stated that "The most important thing is that the United States must be and is ready for any of these contingencies" and was in constant communication with its allies and partners. "We have reassured and reinforced our allies on its eastern flank."
Texas Rep. Michael McCaul was the top Republican on House Foreign Affairs Committee. He attended a classified briefing that administration officials provided to members of Congress last week. He was asked if he thought Russia would attack Ukraine after the briefing.
"I believe the conditions are present. It is more likely than not. The noose seems to be being prepared. As we speak, it's in Ukraine. McCaul stated that these are dangerous times.
Linda Thomas-Greenfield is Biden's Ambassador to the United Nations. She said that while the administration was still looking for a diplomatic solution to the crisis, "at the same, we know the Russians continue their preparations, and we will work to address the security problems."
Senator John Barrasso is a member the Senate Foreign Relations Committee. He stated that Ukraine was the first step in Putin's plan for reassembling the Soviet Union. He was concerned about the signal it could send to U.S. enemies.
"He should choke when he tries to swallow Ukraine. If it's easy for him, then my concern is that China moves against Taiwan and Iran quickly moves to a nuclear weapons."
In the meantime, U.S. troops and equipment arrived in southeastern Poland at the border with Ukraine. This was after Biden ordered 1,700 soldiers to be deployed there amid concerns about a Russian invasion.
Hundreds of additional troops from the 82nd Airborne Division will arrive at Rzeszow–Jasionka Airport. A Boeing C-17 Globemaster aircraft of the U.S. Air Force brought with it a few dozen troops as well as vehicles.
Their commander was Maj. Gen. Christopher Donahue who, on Aug. 30, was the last American soldier that left Afghanistan.
Donahue stated at the airport, "Our contribution here in Poland is a sign of solidarity with all our allies here, Europe, and, obviously, in this period of uncertainty, we know that we can be stronger together."
Biden authorized additional U.S. troops to be deployed to Poland and Romania to show America's support for NATO's eastern flank in the midst of tensions between Russia, Ukraine. NATO's eastern member Poland borders both Russia, and Ukraine. Romania borders Ukraine.
It can deploy quickly within 18 hours and carry out parachute attacks to secure key objectives. The history of the division, which is based in Fort Bragg North Carolina, dates back to 1917.
Biden will meet German Chancellor Olaf Scholz on Monday at the White House. Scholz stated that Moscow would be paying a "high cost" in case of an attack. However, his refusal to supply lethal weapons for Ukraine, strengthen its troop presence in Eastern Europe, or specify which sanctions it would support in relation to Russia has been criticized at home and abroad.
The French President Emmanuel Macron arrived Monday in Moscow to meet with Putin. Scholz will also be there in the days ahead. According to the White House, Biden and Macron spoke on Sunday by telephone to discuss "diplomatic and counter-terrorism efforts in response Russia's continuing military buildup on Ukraine's border."
Sullivan stated that Russia-to-Germany Nord Stream 2's operation "will not proceed" if Russia invades Ukraine. The pipeline construction is complete but the gas has not yet started to flow.
Sullivan stated that, "While it is true that Germany hasn't sent arms to Ukraine but after the United States, they're the second largest donor of Ukraine to Europe." "The best thing about the alliances we have formed with our NATO allies, is that each allie will take different parts of it."
Sullivan was on "Fox News Sunday," NBC’s "Meet the Press", and ABC's" "This Week." McCaul spoke to ABC and Barrasso appeared on Fox. Thomas-Greenfield appeared on CNN's "State of the Union."