The letter was handed over on Thursday after President Donald Trump announced that the United States may need to use British military bases in the event of a possible attack on Iran.
"It would be catastrophic for the region and would pose a serious threat to international peace and security," wrote Amir Saeid Iravani, according to AFP.
He added that all US bases and assets would become "legitimate targets" if the United States attacks Iran.
According to The Times, British Prime Minister Keir Starmer has denied the United States permission to use the country's military bases in an offensive war against Iran.
