WASHINGTON (AP) — President Barack Obama defiantly dared congressional Republicans on Tuesday to try to block his efforts to act on his own and bypass a divided Congress that has thwarted his policy initiatives.

"So sue me," he taunted on a sweltering day, as he pushed lawmakers to pay for road and bridge repairs. "I'm not going to apologize for trying to do something."

Obama struck an aggressive tone in the face of a lawsuit threat from House Speaker John Boehner and in the wake of two defeats before the Supreme Court, including a unanimous decision from the court that he overreached when he appointed members of the National Labor Relations Board while the Senate was in recess.

His remarks came a day after Obama declared that he would act on his own to address weaknesses in the nation's immigration system after Boehner informed him that the House would not take up an immigration overhaul this year.

He has already taken a series of executive actions, including an order requiring federal contractors to pay a higher minimum wage and initiating steps to to lower carbon emissions in coal-fired power plants.

"So far this year, Republicans in Congress have blocked or voted down every serious idea to strengthen the middle class — not ideas that are unique to me," he said. "But the Republicans have said no to raising the minimum wage, have said no to fair pay. They've said no to extending unemployment insurance for over 3 million Americans looking for a new job."

Earlier Tuesday, Obama met with his Cabinet secretaries and urged them to "be creative about how we can make real progress" on issues where Congress won't act.

Obama said he would prefer that Congress act on issues such as immigration and infrastructure because laws are more sweeping than his own administrative actions.

"We're not always going to be able to get things through Congress, at least not this Congress," Obama said. "I want to make sure we emphasize not what we can't do, but what we can do in the coming months."

Speaking at Washington's Key Bridge, Obama in shirt sleeves and his tie undone made a pitch to fix the nation's bridges and highways.

He called on Congress to close tax loopholes and use the money on infrastructure projects, a long shot idea that has little if any support among congressional Republicans.

"It's not crazy. It's not socialism," he said, mocking the criticism from some conservative quarters. "You know, it's not, you know, the imperial presidency or no laws are broken."