President Obama and Iranian President Discuss Nukes by Phone

Sept. 27, 2013— -- President Obama spoke by phone today with Iranian President Hassan Rouhani about ongoing efforts to reach an agreement over Iran's nuclear program, the first time the heads of these two countries have had direct communications since 1979.

"While there will surely be important obstacles to moving forward and success is by no means guaranteed, I believe we can reach a comprehensive solution," the president said in a hastily announced statement in briefing room.

Obama underscored the significance of the phone call.

"The very fact that this was the first communication between an American and Iranian president since 1979 underscores the deep mistrust between our countries, but it also indicates the prospect of moving beyond that difficult history," he said.

The Iranian news agency IRNA confirmed the call and said it took place while Rouhani was in a car and heading towards John F. Kennedy International Airport. Rouhani had been in New York for the United Nations General Assembly.

Rouhani sent a barrage of tweets about the phone call on his way to airport, including one apologizing to New Yorkers who were stuck on traffic as world leaders headed out of town.

His first tweet about the call, however, said,

The call about the Iran's nuclear program came days after Iran's president avoided a face-to-face meeting with Obama. U.S. officials said at the time that it was "too complicated" for the Iranian president to meet Obama and shake hands.

The conversation comes as the new Iranian president has shown a willingness to work with Obama even as his country has not made any concrete steps to fulfill the preconditions that Obama required for negotiations on the nuclear issue.

The Iranians have long-held that they seek nuclear technology to provide energy and not for the development of nuclear weapons.

"I do believe that there is a basis for resolution," Obama said. "Iran's supreme leader has issued a fatwa against the development of nuclear weapons. President Rouhani has indicated that Iran will never develop nuclear weapons. I've made clear that we respect the right of the Iranian people to access peaceful nuclear energy in the context of Iran meeting its obligations. So the test will be meaningful, transparent and verifiable actions, which can also bring relief from the comprehensive international sanctions that are currently in place."

"I believe we've got a responsibility to pursue diplomacy and that we have a unique opportunity to make progress with the new leadership in Tehran. I also communicated to President Rouhani my deep respect for the Iranian people," he said.

As the House of Representatives begins consideration of a continuing resolution to fund the government, President Obama bluntly called on Congress not to shut the federal government down warning of the "dampening effect" it could have on the U.S. economy.

Republicans, the president complained, were too "concerned with appeasing the Tea Party."

Looking ahead to another standoff with Congressional Republicans, Obama reiterated his position that he would not negotiate over the debt ceiling, saying a default would have a "profound destabilizing effect on the economy."

A spokesman for House Speaker John Boehner responded today, calling the president's remarks: "grandstanding."

"The House will take action that reflects the fundamental fact that Americans don't want a government shutdown and they don't want the train wreck that is Obamacare," spokesman Brendan Buck said in a statement. "Grandstanding from the president, who refuses to even be a part of the process, won't bring Congress any closer to a resolution."

The president has not called the speaker this week, aides tell ABC News.

ABC News' Michael Falcone and Jeff Zeleny contributed to this report