Obama also put distance between U.S. and Israeli assessments of when Iran might have the capacity to build a nuclear weapon. Israeli officials have said Iran is just months away from having the capacity and knowledge to build a bomb, while Obama said Tehran was a year or more away.
Israeli Justice Minister Tzipi Livni played down the differences.
'The question isn't the timetable the question is how we get that result," Livni told Israel's Channel 10 TV.
Iranian Foreign Minister Mohammed Javad Zarif disputed Obama's comments, repeating Iran's claims that it is not seeking a nuclear weapon.
The U.S. and Israel contend that Iran's nuclear program is aimed at building a bomb, while Tehran says it is enriching uranium for peaceful purposes.
On domestic issues, Obama said he would be willing to negotiate with Republicans on health care, deficit reduction and spending — but only if House Speaker John Boehner, R-Ohio, holds votes to reopen the government and increase the nation's borrowing limit.
The Treasury Department says the nation will hit its borrowing limit around Oct. 17. Obama didn't specifically rule out taking action on his own if Congress fails to increase the debt ceiling, but said he doesn't expect to get to that point.
Obama, who successfully ran for president as a first-term senator, also spoke critically about first-term Republican senators, such as Ted Cruz of Texas, who have been leading efforts to shut the government if Republicans can't extract concessions from the White House.
The president said that when he was in the Senate, he "didn't go around courting the media. And I certainly didn't go around trying to shut down the government."
"I recognize that in today's media age, being controversial, taking controversial positions, rallying the most extreme parts of your base, whether it's left or right, is a lot of times the fastest way to get attention and raise money," he said. "But it's not good for government."