Mahmoud Ahmadinejad, the former president of Iran, took to Twitter on Sunday to weigh in on the spat between President Donald Trump and LeBron James, the basketball star, at a time of rising tensions between the two countries.

Mr Ahmadinejad was barred from running in last year’s elections but showed he was still intent on returning to the spotlight with the sort of social media intervention that has come to define presidential politics in the wake of Mr Trump’s election.

“In my opinion everyone especially a President should love all, and not differentiate between them," he wrote on Twitter, which is banned in Iran.

He added that he loved NBA greats James and Michael Jordan, as well as former Denver Nuggets player Mahmoud Abdul-Rauf.

Mr Ahmadinejad, who served as president from 2005 to 2013, was known for controversial statements that included questioning whether the Holocaust took place and claiming there were no gays or lesbians in Iran.

His foray into sport commentary may be unusual but as an attack on a sitting US president it is entirely in character.

His thoughts come at a critical time in Iran-US relations. Washington is poised to reintroduce a slew of sanctions and Iran’s Revolutionary Guards on Sunday said it had held war games in recent days.

However, his criticism may not be the most wounding for an American president who has put opposition to Tehran at the heart of his foreign policy. For Mr Trump also faces opposition within the White House from his own wife since delivering a sideswipe against James on Friday night.

It began when the sports star criticised Mr Trump in a CNN interview, designed to promote his work with vulnerable children.

James accused Mr Trump of using sport to divide people.

“Sports has never been something that divides people,” he said, provoking an angry reaction from the American president who ridiculed the basketball player’s intelligence.

However, Melania Trump distanced herself from her husband the next day.

“It looks like LeBron James is working to do good things on behalf of our next generation and just as she always has, the first lady encourages everyone to have an open dialogue about issues facing children today,” she said via her spokeswoman.

Meanwhile, Monday marks the end of a 90-day grace period after which the US will re-impose the first batch of sanctions since Mr Trump pulled Washington out of the Iran nuclear deal. They cover the purchase of dollar banknotes, the trade in precious metals and the automotive sector among others.

Iran's economy has deteriorated rapidly in recent weeks due in part to uncertainty over sanctions. Protests have been reported in several cities during the past week.

At the same time, US officials say Iran has been carrying out naval drills – with as many as 100 vessels - in the Gulf to demonstrate readiness.

Ramezan Sharif, a spokesman for the Revolutionary Guards, told state media: "This exercise was conducted with the aim of controlling and safeguarding the safety of the international waterway and within the framework of the programme of the Guards' annual military exercises.”