''The answer is: No regrets," the president told NBC television on the sidelines of a visit to a middle-class family aimed at highlighting his efforts to revive the sputtering US economy ahead of November congressional elections.
Obama upset some of his Democratic allies late last week by joining a bitter national debate over the plans, affirming the right to build on religious freedom grounds but without endorsing what he called the "wisdom" of doing so.
His remarks drew immediate fire from his Republican foes, including possible contenders for the White House in 2012, who have denounced the project as offending the memory of those killed in the attacks.
And Democratic Senate Majority Leader Harry Reid, facing a stiff reelection challenge, came out against the project just days after Obama spoke after Reid's Republican rival Sharron Angle pressed the veteran lawmaker on the issue.
Some Democrats reportedly worried that Obama's comments would give the controversy fresh prominence in races around the country at a time when at least one opinion poll has found the public deeply uneasy about the project.
The president's remarks came as Democratic US House Speaker Nancy Pelosi said that the fate of the project -- an Islamic community centre two blocks from Ground Zero -- was a "local decision."