WASHINGTON (AP) — President Barack Obama prodded Congress Tuesday to send him a bill by fall remaking the nation's immigration laws, even as the Senate prepared to cast its first floor votes on the landmark measure opening a door to citizenship for millions.

"Congress needs to act, and that moment is now, " Obama said, surrounded by immigration advocates, business and religious leaders, law enforcement officials and others in the East Room of the White House.

"There's no reason Congress can't get this done by the end of the summer," the president said. "There's no good reason to play procedural games or engage in obstruction just to block the best chance we've had in years to address this problem in a way that's fair to middle class families, business owners and legal immigrants."