OKLAHOMA CITY (AP) -- Mitt Romney says he believes marriage should be restricted to one man and one woman and that he's held that view "since running for office."

Romney on Wednesday called same sex-marriage "a very tender and sensitive topic" as he contrasted his position with President Barack Obama's unequivocal declaration of support Wednesday for allowing same-sex couples to marry.

Obama is the first president in history to support gay marriage. Polls show the country is evenly divided on the issue.

Romney did not go so far as to accuse Obama of changing his position on the issue. Questioned by reporters, the presumptive Republican nominee for president said news reports indicate Obama has shifted his stance.

Romney says states should be able to decide whether to grant certain legal benefits to same-sex couples.