Iran's foreign minister will meet major powers this week on Tehran's nuclear program in what could be a historic top-level contact with the United States, the EU said Monday.

Catherine Ashton, the European Union's foreign policy chief, announced the meeting after what she called a "good and constructive" meeting at the UN headquarters with the foreign minister of Iran's new government, Mohammad Javad Zarif.

Ashton said that Zarif had agreed to join a meeting of six powers that are negotiating with Iran on its contested nuclear program -- Britain, China, France, Germany, Russia and the United States.

Western nations accuse Iran of seeking a nuclear bomb capability. Iran's new president, Hassan Rowhani, said last week that his country would "never" build a bomb.

The landmark meeting, expected Thursday, should include US Secretary of State John Kerry, although US officials did not immediately confirm that he would take part.

A meeting between Kerry and Zarif would be a milestone between the United States and Iran, which have had no diplomatic relations since the 1979 Islamic revolution that toppled the Western-oriented shah.

Ashton said that she would also meet more formally with Zarif and the two sides' advisers in Geneva in October.

Ashton voiced hope for progress, although she played down expectations of a breakthrough.

"I was struck by the energy and determination on the part of the minister," Ashton said.

But she said, "As you would appreciate, there is a huge amount of work to do."

US President Barack Obama has pledged to test whether Rowhani, who is considered a moderate within the clerical regime, is serious about resolving Western and Israeli concerns about Iran's nuclear program.

Obama and Rowhani both sounded upbeat after an exchange of letters.

The White House has not ruled an encounter at the UN General Assembly this week, but has said that there are no current plans. Both leaders will address the assembly on Tuesday.

Iran says its nuclear work is meant for peaceful purposes, with Rowhani telling NBC News in a recent interview that his country will "never" seek a nuclear bomb.

But Western nations have voiced skepticism over Iran's intentions, with the United States spearheading sanctions that have ravaged the Iranian economy.

Israeli Prime Minister Benjamin Netanyahu has criticized overtures to Rowhani, calling him a "wolf in sheep's clothing" and urging no let-up in pressure.

Zarif, who was educated in the United States and speaks English, is known and respected by Western diplomats.

Greg Thielmann, a senior fellow at the Washington-based Arms Control Association, saw potential signs of progress in jumpstarting diplomacy on Iran.

"You've got all these signals from the Iranians that they are willing and trying to be more constructive," Thielmann said.

"Zarif has this reputation as someone who understands the West well, so if Kerry himself is involved it would be a very significant milestone," he said.

Rowhani is to meet on Tuesday with French President Francois Hollande, who said that Iran requested the talks to discuss the civil war in Syria in which Tehran and the West are on opposite sides.

Rowhani is expected to set a different tone at the United Nations than his predecessor Mahmoud Ahmadinejad, who sparked controversy with his strident threats against Israel and by casting doubt on the Holocaust.

AFP