A BID by Britain to defuse escalating tensions between the US and Iran has stumbled as a top Iranian diplomat described talks as “repetitive”.

It leaves America and Iran still “eyeball to eyeball”, with relations between the two countries almost at boiling point.

Foreign Office minister Andrew Murrison held talks with the Tehran government, calling for “urgent de-escalation” and raised UK concerns “about Iran’s regional conduct and its threat to cease complying with the nuclear deal”, according to a statement by the Foreign Office.

The trip was announced after Donald Trump said the US was “cocked and loaded” to retaliate against Iran for downing an American drone on Thursday.

The strikes were reportedly called off 10 minutes before they were to be carried out after Mr Trump was told 150 people could die.

Dr Murrison’s visit also came after the US accused Iran of attacking oil tankers earlier this month – which Iran denies.

He said following talks: “This visit has provided an important opportunity for open, frank and constructive engagement with the Iranian Government. In Tehran I was clear about the UK’s long-held concerns over Iran’s activities in the region.

“I reiterated the UK’s assessment that Iran almost certainly bears responsibility for recent attacks on tankers in the Gulf of Oman. Such activity, which carries a high risk of miscalculation, needs to stop to allow for immediate de-escalation of rising tensions.

“And I was clear that the UK will continue to play its full part alongside international partners to find diplomatic solutions to reduce the current tensions.

“I reiterated the UK’s determination to maintain the nuclear deal which is in our shared security interests.”

But Kamal Kharazi, head of the Strategic Council of Foreign Relations at Iran’s Foreign Ministry, said Dr Murrison had only the “usual talking points”.

He said these included a European payment mechanism to help Iran with US sanctions and “that Britain has always supported the Joint Comprehensive Plan of Action (known commonly as the Iran nuclear deal or Iran deal)” but he added that “such talks have always been repetitive”.

Britain is a signatory to the 2015 nuclear deal which saw Iran scale back its nuclear programme in exchange for sanctions relief.

Iran’s president accused the United States of fuelling the fire in an already volatile region.

The official IRNA news agency quoted Hassan Rouhani as saying the “interventionist military presence” of the US is responsible for the Middle East’s problems.

On Saturday, a spokesman for Iran’s armed forces warned that a military strike would “set the region ablaze and burn up the US, its interests, and its allies”.

Mr Trump later tweeted that the US will impose “major additional sanctions” on Iran after opting to halt military action “from going forward at this time”.

Former Foreign Secretary David Miliband said we are now in the midst of a “pressing global threat to peace and security”.

Mr Miliband told BBC One’s The Andrew Marr Show: “The current Foreign Secretary has real responsibilities at the moment. I don’t think we can afford him to be completely absent from the stage. Britain is a permanent member of the security council. This is a pressing global threat to peace and security.

“We’re relying on the caution of President Trump to keep the hawks at bay in his own administration.”

Responding to what Mr Miliband said, Mr Hunt wrote on Twitter: “Agree, and thankfully I’m not. Speaking regularly to my counterparts on this subject, including Sec Pompeo, have sent a minister to the region, and will be updating parliament on Tuesday. Extremely serious situation.”

Dr Murrison’s visit amid the bellicose exchanges between Washington and Tehran is part of the UK’s “ongoing diplomatic dialogue with Iran”, the Foreign and Commonwealth Office (FCO) said.

Mr Trump pulled out of a long-term deal struck with Iran in 2015 to limit its sensitive nuclear activities and allow in international inspectors in return for the lifting of economic sanctions.

The deal was signed by his predecessor Barack Obama along with the UK, France, China, Russia and Germany, which still support the agreement.

But Mr Trump declared it a “terrible” deal and imposed more sanctions.

On Saturday, German chancellor Angela Merkel called for a “political solution” on Iran, saying such a result “should not just be a hope, but it should be worked towards with the utmost seriousness”.

Tensions between the US and Iran have increased in recent weeks amid claims by Washington that Tehran has been behind attacks on oil tankers in the Persian Gulf.

Dr Murrison’s visit also took place amid continuing tension between London and Tehran over the treatment of Nazanin Zaghari-Ratcliffe, a British-Iranian dual citizen who has been detained in Iran since April 2016 accused of spreading propaganda against Iran.

Her husband Richard Ratcliffe has been on a hunger strike outside the Iranian Embassy in London in support of his wife who is also on hunger strike.

Dr Murrison said he raised the issue, adding: “While in Tehran, I also pressed again on behalf of the UK Government for the urgent and unconditional release of Nazanin Zaghari-Ratcliffe and all British-Iranian dual nationals who are being arbitrarily detained.”

Meanwhile, a top Iranian military commander warned yesterday that any conflict with Iran would have uncontrollable consequences across the region and endanger the lives of US forces.