IRNA � Iran's missile power is non-negotiable, the spokesman of the Iranian government said on Tuesday.

Iran will not negotiate with such an 'instable', 'erratic' state as the US, Mohammad Baqer Nobakht said in a press conference, stressing that 'Iran's missile power is non-negotiable whatsoever.'

'We will spare no effort to boost our defensive power,' he added.

Currently a party has made a claim for paving the way to pull out of the nuclear deal, but China, Russia and the European Union want to maintain the deal, and have made some comments on the issue, Nobakht said.

Iran and the five permanent members of the UN Security Council plus Germany singed a nuclear deal in 2015, known as the Joint Comprehensive Plan of Action (JCPOA). Iran accepted to limit its nuclear activities in exchange for sanctions relief.

However, Trump has called the agreement 'the worst' deal the US has ever entered into. He has threatened that he may withdraw from the deal or renegotiate it. Trump has also accused Iran of violating the 'spirit' of the deal.

The International Atomic Energy Agency (IAEA) has verified Iran commitment to the deal eight times. The US administration has also certified it two times since Trump has taken office in January 2017.

'Let's try towards laying grounds for further unity among all countries on maintaining JCPOA,' Iranian governemnt's spokesman said.

'Mr. Amano also announced once more that he would take due measures on the issue, and Iran's stance is that it will not step back from its national interests,' the spokesman said.

The head of the United Nations nuclear watchdog reaffirmed that Iran has been committed to the nuclear deal it signed with the major world powers. Addressing the 20th Edoardo Amaldi Conference in Rome on Monday, Yukiya Amano said : 'I can state that the nuclear-related commitments undertaken by Iran under the JCPOA are being implemented.'

Speaking on any talk between Iran and the US on other issues, he said that given the past record of the US, it is clear that Washington is not a reliable, trustworthy party to sit at a negotiation table.