The U.S. was preparing thousands of troops who could be called upon to support NATO after the alliance on Friday activated a rapid response force in the wake of Russia's invasion of Ukraine, the Pentagon said.
The activation by President Joe Biden and leaders of member states marks the first such use of the NATO Response Force to guard alliance territory, which does not include Ukraine. But it remained unclear how many American service members could participate as the alliance was still weighing its needs.
Secretary General Jens Stoltenberg said the force would be sent to the alliance's eastern flank, which borders Ukraine and the ongoing war triggered by Russia's invasion, according to The Associated Press.
Some of the 7,000 troops that Biden said on Thursday will deploy to Germany could also be part of the NATO force, though the U.S. and NATO members have made clear it would not be sent to fight Russia in Ukraine. The U.S. has already deployed about 12,000 troops and equipment such as F-35 Lightning II fighter jets and Apache attack helicopters to Germany, Poland, Romania and the Baltic states.
"We are going to provide additional security assistance for Ukraine -- we will," Pentagon spokesman John Kirby said. "How that is going to be done is still being worked out."
The Pentagon has said more than 11,000 troops have been put on heightened alert for deployment since January, but it could not provide exact figures on Friday of those who remain on alert or have been deployed.
Gen. Tod Wolters, the head of U.S. European Command who also serves as the NATO Supreme Allied Commander Europe, said the alliance activation on Friday was a "historic moment." The NATO Response Force is described by the organization as a "highly ready and technologically advanced" group of 40,000 troops from member nations.
Biden said Thursday the 7,000-troop deployment will include the 1st Armored Brigade Combat Team, 3rd Infantry Division, out of Fort Stewart, Georgia.
The NATO activation came as Russia pushed farther into Ukraine and continued to threaten the Ukraine capital, Kyiv, after launching an invasion Wednesday. Progress appeared to be slowing, with Russian troops facing more resistance from Ukrainian forces than anticipated.
"It's looking like they're trying to reach the capital as fast as they can to encircle Kyiv," Michael Kofman, an adjunct senior fellow with the Center for a New American Security think tank, said during a briefing event Friday. "It also looks like they're attempting large pincer movements to try to cut off and encircle big parts of the Ukrainian military in the east and south of the country."
Earlier Friday, the Ukrainian military still had command-and-control capabilities and was flying air offensives against Russian forces, according to a senior defense official who briefed the press on the situation on the condition of anonymity. There was intense fighting in the capital as well as at a hydro-electric dam, and Russia was staging an amphibious landing in the east of the country along the Sea of Azov.
"I think they [the Russians] tried something that at best had very mixed results for them," Kofman said, cautioning that it was still very early in the invasion. "I think the things they're trying aren't necessarily working very well right now, but they're likely going to adjust."
Russia had deployed only about one-third of the more than 150,000 troops it had staged around Ukraine's borders in the buildup before the invasion, the defense official said.
The fighting had already started a flood of refugees fleeing from Ukraine across neighboring borders. Several hundred Americans had crossed from Ukraine to Poland between Thursday and Friday. The Army's 82nd Airborne Division from Fort Bragg, North Carolina, has set up in Poland to train with its forces and prepare to help U.S. citizens trying to escape.
Before invading, Russian President Vladimir Putin demanded that Ukraine, a former Soviet republic along its western border, never be allowed to join the West's 30-nation NATO alliance, which has expanded dramatically over the past few decades.
Putin carved off and annexed Ukraine's Crimea peninsula in 2014 following a coup that ousted the Moscow-aligned president and government, and has since fueled a years-long separatist conflict between the new pro-western government in Kyiv and the heavily ethnically Russian region of Donbas in the eastern part of the country.
-- Travis Tritten can be reached at email@example.com. Follow him on Twitter @Travis_Tritten.