Trump has sent a major deployment of air and sea power to the Middle East and has threatened to strike Iran if it does not reach a deal on key concerns starting with its nuclear programme.

"We call upon all nations committed to peace and justice to take meaningful steps to prevent further escalation," Gharibabadi said at the Conference on Disarmament in Geneva.

"The consequences of any renewed aggression wouldn't remain confined to one country -- and responsibility would rest with those who initiate or support such actions."

Iranian and US negotiators held indirect talks in Geneva last week on Tehran's nuclear programme, hosted by Oman.

Washington said Monday that nuclear talks with Iran will resume on Thursday, with Oman having earlier said they would again take place in Geneva.

"The Islamic Republic of Iran remains committed to diplomacy and dialogue as the most effective path towards de-escalation and sustainable security," Gharibabadi said.

"Recent diplomatic engagement here in Geneva, which will continue this Thursday, demonstrates that a new window of opportunity exists for negotiations to address differences and build confidence -- provided that they uphold mutual respect, equitable treatment and non-selective application of international norms.

"Any sustainable and credible negotiation must respect the legitimate rights of all states under international law, and deliver tangible security benefits without coercion, unilateral demands or threats of force."

- 'Critical crossroad' -

The United States and Israel threatened new military action against Iran after mass protests in the Islamic republic, which the Iranian authorities crushed at a cost of thousands of lives.

Daniel Meron, Israel's ambassador to the UN in Geneva, told reporters his country would be following Thursday's talks "very closely".

Gharibabadi said that while Tehran sought the path of diplomacy, it was prepared to defend its sovereignty, territory and people, insisting it would exercise its right to self-defence "if necessary".

He called upon nuclear-armed states to offer legally binding security assurances for countries without atomic weapons.

Shen Jian, China's ambassador to the disarmament forum, said the Iran nuclear issue stood "at a critical crossroad".

"We oppose unilateral bullying and the use of force in international relations," he said, calling for a "favourable environment" for the ongoing diplomatic efforts.

"Avoid pushing the Iranian nuclear issue toward a confrontation or triggering new conflicts," Shen added.