White House press secretary Josh Earnest said Obama "and his successor will be able to coordinate effectively with her to not just protect but even advance the special relationship" between the two countries.
During a media briefing in Washington D.C., Earnest said: "The president, though, continues to rest on a principle that the relationship between the United States and the United Kingdom is a special one.
"And, it is a relationship that transcends the personalities or political parties of either country's leader.
"And, if in fact, Theresa May is the next prime minister of the UK, the president is entirely confident he and his successor will be able to coordinate effectively with her to not just protect but even advance the special relationship between our two countries," Earnest added, according to the Telegraph.
May will tomorrow become leader of the Conservative party, and thus prime minister, after David Cameron finishes his final round of Prime Minister's Questions.
However, the Liberal Democrats and Labour are pushing for a snap general election due to the change of leadership.
It also emerged yesterday that May had previously called for Gordon Brown to hold a snap election when he replaced Tony Blair, questioning the Labour man's mandate.