Political directors from the UN Security Council permanent members - Britain, China, France, Russia and the United States - plus Germany will meet Wednesday near the western city of Frankfurt, German Foreign Ministry spokesman Jens Ploetner told a news conference.
Although the political directors are in constant telephone and email contact about Iran's nuclear programme, the meeting will mark the first gathering since Obama took office on January 20.
In an interview Monday with Al-Arabiya television, Obama vowed to map out a new future for US relations with Iran after a three-decade diplomatic freeze.
But the new administration has refused to rule out any options - including military strikes - to stop Tehran from acquiring a nuclear weapon.
German Foreign Minister Frank-Walter Steinmeier welcomed the new approach from Washington in a parliamentary speech on Friday, saying the problem with Iran could only have a "diplomatic solution."
"It is good that Obama extended his hand and showed willingness to hold direct talks with Iran," he said, calling on Iran "not to rebuff that hand."
Iran's hardline President Mahmoud Ahmadinejad unleashed a fresh tirade against the United States this week, demanding Obama apologise for past US "crimes" against the Islamic republic.
The six powers offered Tehran a set of economic and energy incentives in exchange for halting its uranium enrichment programme which the West sees as a cover to acquire nuclear weapons capability.
But Tehran is pressing on with its sensitive nuclear fuel work, insisting that its nuclear programme is peaceful and solely geared toward electricity generation.
Germany said Monday it had drastically cut its export guarantees for companies trading with Iran.
Berlin's move came amid increased criticism, notably from the United States and Israel, over Germany's growing trade with Iran.
Exports to Iran rose 10.5 percent in the first 11 months of 2008 to reach €3.6 billion ($4.6 billion), according to government statistics.