Obama brushed off Republicans who complain that the president's pledge not to attack nations that abide by nonproliferation treaties tips the hand of U.S. strategy to the world.

Asked specifically whether or not he had a response to Palin, one of his potential 2012 opponents, Obama said he had none.

"I really have no response," he said during an interview on "Good Morning America" on ABC. "Because last I checked, Sarah Palin's not much of an expert on nuclear issues."

Obama unveiled his new strategy ahead of signing a nuclear arms reduction treaty with Russian President Dmitry Medvedev during a summit these past two days in the Czech Republic. World leaders will also gather in Washington next week for a summit on nuclear security.

The president said that he wouldn't rely on the GOP for advice when he has access to top military and civilian officials.

"What I would say to them is that if the secretary of defense and the chairman of the Joints Chiefs of Staff are comfortable with it, I'm probably going to take my advice from them and not from Sarah Palin," he said.