Iran will take new steps to reduce its commitments under its nuclear deal with world powers on July 7, the Secretary of the Supreme National Security Council, Ali Shamkhani, said on Tuesday, according to the Fars news agency.

Shamkhani said European signatories to the nuclear deal had not done enough to save it. The 2015 deal requires Iran to curb its nuclear programme in return for the lifting of sanctions which were reimposed last year after the United States had withdrawn from the deal.

Iran says it intends to continue complying with the deal but cannot do so indefinitely unless European countries find ways to protect it from US sanctions.

Britain has declared it has no intent to enter into the conflict.

Britain does not expect the United States to request that the United Kingdom join a war with Iran and London would be unlikely to agree to join such a conflict, Foreign Secretary Jeremy Hunt said on Tuesday.

“The US is our closest ally, we talk to them the whole time, we consider any requests that they say carefully, but I cannot envisage any situation where they request or we agree to any moves to go to war,” Hunt told parliament.

“The message we are sending with our partners in the European Union particularly the French and the Germans is that with respect to Iran's nuclear programme, this is a crucial week.

“It is absolutely essential that they stick to that deal in its entirety for it to preserve and for us to have a nuclear free middle east,” Hunt said.

Meanwhile, the Iranian foreign minister on Tuesday sought to assert Iran's position on its nuclear programme.

Iran will never pursue a nuclear weapon, Foreign Minister Mohammad Javad Zarif said, according to the IRIB news agency.

He pointed to the past use of nuclear weapons by the United States and to recent comments by US President Donald Trump that he had called off a military strike on Iran because it would have killed 150 people.

“You were really worried about 150 people? How many people have you killed with a nuclear weapon? How many generations have you wiped out with these weapons?” Zarif said.

“It is us who, because of our religious views, will never pursue a nuclear weapon,” he added.

'Mentally retarded'

Iranian President Hassan Rouhani dismissed new sanctions by the United States on Iran's Supreme Leader Ali Khamenei and described the White House as “mentally retarded”, an insult Iran has used in the past about President Donald Trump.

In a speech broadcast live on state television, Rouhani said sanctions against Iran's Supreme Leader Ayatollah Ali Khamenei would fail because he had no assets abroad. Rouhani described the latest round of sanctions as a sign of US desperation.

“The White House actions mean it is mentally retarded,” he said “Tehran's strategic patience does not mean we have fear."

President Trump signed an executive order on Monday, imposing financial sanctions on Khamenei and other Iranian officials. The targets of the new sanctions also include senior military figures in Iran, blocking their access to any financial assets under US jurisdiction.

The sanctions come days after Iran downed a US drone that it said had trespassed its airspace.

Trump pulled back from the brink of retaliatory strikes on Iran last week, but appears to be continuing to ratchet up his "maximum pressure" campaign.