Joe Biden said it may be time for a British Nato leader in a boost for Ben Wallace’s hopes of taking the alliance’s top job.
The prospect of the Defence Secretary taking the role was raised in talks between Rishi Sunak and the US president at the White House.
Mr Biden appeared to indicate Mr Wallace was a “very qualified individual” but it “remains to be seen” who will get the job.
Nato’s current secretary general Jens Stoltenberg steps down at the end of September.
The last Briton to lead the alliance was Lord Robertson, who held the role between 1999 and 2003.
Asked if it was time for another Briton to lead the alliance, Mr Biden said: “Maybe, that remains to be seen.
“We are going to have to get a consensus within Nato to see that happen.
“They have a candidate who is a very qualified individual.”
But, he added, there would have to be “a lot of discussion” at Nato to determine the outcome of the process.