Defence leaders are in the process of developing options for President Joe Biden on America's military presence in Europe, the Pentagon's top officer told the Senate on Thursday.
Chairman of the Joint Chiefs of Staff Gen Mark Milley told the Senate Armed Services Committee that a list of options will be presented to Mr Biden and Secretary of Defence Lloyd Austin pertaining to reconfiguring US posture in Europe.
The goals are “to assure our allies and deter an adversary, specifically Russia”, he said.
Mr Austin told the committee that Russia’s invasion of Ukraine will undoubtedly change the US military footprint across Europe, but the degree of those changes has yet to be determined.
Those decisions are likely to be made at the next Nato summit on June 29, Mr Austin said.
The US currently has troops deployed across Eastern Europe and nearly 100,000 across the continent. While it has permanent bases across Western Europe, US troops in the East are rotated through facilities run by ally countries.
The defence chief told Congress that Moscow has not engaged in military dialogue with Washington since mid-February. “We've not been very successful because the Russians have not responded,” Mr Austin said.
Asked if he was alarmed by the snub, the US defence secretary said he was “disappointed".
“Based upon what they've done, nothing surprises me. And it doesn't mean that we'll stop reaching out to engage them," he said.
Both Mr Austin and Gen Milley expect a prolonged conflict in Ukraine.
“There's a significant battle yet ahead down in the south-east, down around the Donbas region where the Russians intend to amass forces and continue their assault,” Gen Milley said.
He argued that it is still an open question as to how the war will end, despite the Russian retreat from Kyiv.
“Ideally, [Russian President Vladimir] Putin decides to [implement a] ceasefire, stops his aggression, and there’s some sort of diplomatic intervention, but right now that doesn't look like it's on the immediate horizon,” Gen Milley said.
“It's going to be a long slog.”
Mr Austin saw Russia as refocusing on an offensive on the east and south of Ukraine.
“Putin thought that he could very rapidly take over the country of Ukraine, very rapidly capture this capital city, he was wrong … Putin has probably has given up on that,” Mr Austin said.
Ukraine has received about 25,000 anti-aircraft weapons systems and 60,000 anti-tank systems from the US and its allies, helping Kyiv prevent Russia from establishing air superiority that would have aided Moscow's ground invasion, Gen Milley said.
“The Ukrainians … are very, very thankful, extraordinarily thankful,” Gen Milley told the committee.