"The two leaders discussed the status of diplomatic efforts to bring Iran into compliance with its international obligations on its nuclear program," a statement said after Obama spoke by telephone with French President Nicolas Sarkozy.
The call came ahead of an October 1 meeting between Iran and the United States, Russia, China, Britain, France and Germany set to test Tehran's readiness to discuss concerns over its nuclear program, which Western governments and Israel suspect is a cover to build an atomic bomb.
Iran maintains the program aims to develop nuclear energy for peaceful purposes.
The UN Security Council has imposed three sets of sanctions against Iran over its refusal to freeze its uranium enrichment activities. And Washington has threatened to push for new sanctions if engagement with Iran fails.
The six powers — which represent the five veto-wielding permanent members of the UN Security Council plus Germany — had called for urgent talks with Iran after it handed over proposals for talks last week.
Washington expressed disappointment with the package, saying it was "not really responsive to our greatest concern" — the nuclear issue — but Moscow said it offered "something to dig into."
The upcoming meeting represents a "fulfillment" of Obama's pledge to engage with the Islamic Republic despite three decades of hostility between Washington and Tehran, US Secretary of State Hillary Clinton said.
"We have made clear to the Iranians that any talks we participate in must address the nuclear issue head on. It cannot be ignored," even though Tehran has so far ignored such appeals, she added.
Sarkozy and Obama also discussed efforts to breathe life back into the stalled Middle East peace talks and "agreed to continue working with key players in the Middle East region on setting the conditions necessary to restart Israeli-Arab peace negotiations," the White House said.
During their 30-minute telephone conversation, the two heads of state pledged to work together to ensure next week's G20 summit in Pittsburgh is a success and prepared groundwork for the banking and finance meeting, according to Sarkozy's office at the Elysee Palace.
The presidents "agreed to work closely to make the Pittsburgh meeting a success and allow new decisions to be taken which ensure lasting and balanced growth," it said.
Obama has said he is opposed to a cap on bankers' bonuses, while Sarkozy and other European leaders have backed the idea of tying bankers' payouts to financial performance.
The pair also discussed "the need to address a broad range of regulatory reform issues, including capital and executive compensation," as well as "ways to reform international institutions to make them more inclusive and effective," the White House said.
