U.S. House Speaker Paul Ryan said on Tuesday that it was not possible to end birthright citizenship with an executive order, after President Donald Trump said he was considering such a move, the Washington Post reported.

"You cannot end birthright citizenship with an executive order," Ryan, the top Republican in Congress, said in an interview with radio station WVLK, according to the Post.

Most people born in the United States are legally entitled to U.S. citizenship, according to the U.S. Constitution and court decisions.