An Iranian delegation led by Deputy Foreign Minister Abbas Akhoundi arrived in Washington on Thursday for a second round of talks with US officials on the sidelines of the UN General Assembly, in a rare diplomatic breakthrough that has rattled the nuclear negotiations with Tehran.

The two sides are expected to reach a comprehensive framework for the nuclear talks, which are due to conclude in Geneva later this month, Iranian officials have said.

However, Iranian President Hassan Rouhani has said that the negotiations are not in any shape to lead toward war, and that the nuclear issue will remain “an obstacle” in their efforts to resolve the crisis over Tehran’s nuclear programme.

“I do not think there will be war,” he told the Iranian media.

“We are trying to find a way out of this issue.

The world is not ready for war, we are trying not to be provoked by war.”

The two-day talks will focus on the Iranian nuclear programme, which Iran says is peaceful.

The United States and its allies believe that Iran is trying to develop nuclear weapons for a possible long-term military capability.

Iran has rejected the claims.

It has dismissed such assertions as part of a hostile plot by the West.

Iranian Foreign Minister Mohammad Javad Zarif told the press on Thursday that the talks had “the potential of creating a new chapter in the nuclear deal between the United States, the European Union and Iran”.

“We hope that the dialogue can lead to a new stage in the talks and an agreement for resolving the issues,” he said.

The talks are set to be the most extensive on the nuclear matter since the talks collapsed in 2014, when the US, Britain, France and Germany withdrew their support for the agreement.

Iran is demanding a halt to enrichment activities in return for a lifting of sanctions.

Washington, however, says that any new framework must include an end to enrichment activity.

Iran says it will not stop enriching uranium, but says it is only trying to achieve a peaceful nuclear program.

It says it has no intention of building nuclear weapons and is not seeking a nuclear weapon.