IRAN warned of “the mother of all wars” today in the face of intensified US provocation, yet also indicated that peace between the two countries may still be possible.

President Hassan Rouhani promised that Iranians would remain united against aggression and warned they “will certainly defeat America” should Washington launch an attack on the Islamic Republic.

He told the US: “Don’t play with the lion’s tail, this would only lead to regret” adding: “The Americans must understand well that peace with Iran is the mother of all peace, and war with Iran is the mother of all wars.”

Mr Rouhani was speaking a day after the Supreme Leader Ayatollah Ali Khamenei said he would block all oil exports by closing the Strait of Hormuz should Iranian exports be banned.

He made the comments after US officials travelled to Europe and Asia last month, pressing allies to isolate the “stream of Iranian funding.”

The US has threatened secondary sanctions against those countries that refuse to cut imports of Iranian crude oil — a key source of revenue for Tehran.

“We have a lot of diplomatic muscle memory for urging, cajoling, negotiating with our partners to reduce their investments to zero,” the State Department said.

Mr Khamenei said his statements “were important remarks that reflect the Islamic Republic’s approach,” and urged the country’s Foreign Ministry to follow his advice.

US President Donald Trump’s administration claimed to have asked for meetings with Tehran on eight occasions after it imposed new sanctions on Iran following its withdrawal from the Joint Comprehensive Plan of Action (JCPOA) nuclear deal earlier this year.

He claimed that Iranian leaders were almost certainly “going to call me and say ‘let’s make a deal’.”

However Mr Khamenei said that there was no point in entering discussions with Washington.

“The word and even the signature of the Americans cannot be relied upon, so negotiations with America are of no avail,” he said.

Mr Trump was widely criticised after pulling the US out of the JCPOA earlier this year with all other parties stressing their strong commitment to the agreement.

•At least 25 people were injured in an earthquake close to the Iraqi border yesterday morning.

“Up to now, we have had reports of 25 injured and fortunately no fatalities,” Houshang Bazvand, Governor of Kermanshah, told Iranian state media.