Speaking at a White House briefing, Vance said Washington wanted European allies to "take more ownership" of collective defence.
"We're not talking about pulling every single American troop out of Europe," Vance said, as cited by the Reuters news agency. "We're talking about shifting some resources around in a way that maximizes American security. I don't think that's bad for Europe."
'We've not reduced the troop levels in Poland'
Responding to a question from Polish Radio's Washington correspondent Marek Wałkuski, Vance said the Pentagon had not reduced troop levels in Poland.
"We've not reduced the troop levels in Poland by 4,000 troops," he said. What we did is that we delayed a troop deployment that was going to go to Poland, that's not a reduction, that's just a standard delay in rotation that sometimes happens in these situations," Vance said.