TEHRAN - Iranian Foreign Minister Mohammad Javad Zarif said on Tuesday there is a “historic opportunity” to resolve Iran’s decade-long nuclear showdown with world powers.

“We have a historic opportunity to resolve the nuclear issue,” if world powers adjust to the “new Iranian approach,” Zarif said, without elaborating, in a tweet from New York where he is attending the UN General Assembly.

His comments come a day after he met EU foreign policy chief Catherine Ashton in New York on restarting nuclear talks with the so-called P5+1 group - United States, Britain, France, China and Russia plus Germany. Western powers and Israel have long accused Iran of seeking an atomic weapon under the guise of its civilian nuclear drive, charges adamantly denied by Tehran.

Iran’s new President Hassan Rowhani has promised constructive engagement and increased transparency over the programme in exchange for the easing of crippling international sanctions.

Rowhani is expected to address the General Assembly later Tuesday, in a speech closely followed by the West for confirmation that the moderate president’s pledge is real.

Meanwhile, a meeting between Iran’s top diplomats and world powers at the United Nations this week will start a “new era” in efforts to end the dispute with the West over Tehran’s disputed nuclear program, the Iranian foreign ministry said on Tuesday.

It did not hint at any concessions by Tehran. The European Union said on Monday Iranian Foreign Minister Javad Zarif would join a meeting of major powers - including Britain, France, China, Russia and the United States and Germany - to discuss the Iranian nuclear program.

The meeting, due on Thursday and expected to include US Secretary of State John Kerry, would be the highest-level encounter involving the two nations since relations were severed in 1980 at the height of the US embassy hostage crisis.

“These talks are the start of a new era. The Islamic Republic has explicitly stated its views regarding its rights to peaceful nuclear energy and the right to enrich (uranium) on Iranian territory,” foreign ministry spokeswoman Marzieh Afkham told a news conference, Mehr news agency reported.

“This meeting represents a serious commitment of the foreign parties to reach a solution based on a specified time-frame.”

Before leaving for New York on Monday, newly elected President Hassan Rouhani said he wanted to present Iran’s “true face” and to pursue talks and cooperation with the West to end the nuclear dispute.

Iran says it is enriching uranium only to fuel a planned network of nuclear power stations, and for medical purposes.

The United States and its allies have imposed tough economic sanctions on Iran over suspicions that it is seeking a nuclear weapons capability.

Refined uranium can provide the fissile material for nuclear bombs if processed further, which the West fears may be Tehran’s ultimate goal given that Tehran has a history of hiding some nuclear activity from UN anti-proliferation inspectors.

US officials have also said a meeting is possible this week between President Barack Obama and Rouhani, who are both due to address the General Assembly on Tuesday.

But on Tuesday, Afkham appeared to play down this possibility, telling reporters: “No programme has been organised for a meeting and it is rather (a) discussion in the media.”