The Islamic Republic issued another veiled threat against the British monarchy at the same time
British Armed Forces are on standby after Tehran threatened to target British airbase RAF Fairford.
Donald Trump gave the green light to launch a B1 bomber from the base in Gloucestershire to carry out strikes against the Islamic Republic on Tuesday.
In response, Iran's top military chiefs declared that "any base used to invade Iranian territory is our legitimate target".
On the first day of his premiership, Mr Burnham agreed to let the US use British bases for "defensive" strikes against Iran.
The settled arrangement allows American military to use the Diego Garcia airbase in the Chagos Islands for the same purpose.
The bomber, which can carry more than 20 2,000lb bombs and is able to travel at the speed of sound, was used to hit Islamic Revolutionary Guard Corps (IRGC) targets, Axios reported.
The IRGC, which Britain has now proscribed, accused the US of "resorting to using B1 aircraft flying from Fairford" due to depleted stockpiles.
The authoritiarian regime added another eerie warning, issuing a veiled threat against the Royal Family.
As part of its aggravated response, Iran heaped blame onto the British institution for the "misfortunes" of Iranians across the region.
Military chiefs added that the Family had a "dark record of dividing Islamic countries, widespread massacres in these countries and imposing authoritarian Governments".
And, "worst of all", the Islamic Republic accused the Family of "organising and leading the occupation of Palestine".
"It has participated most in the recent aggressions of the United States and the Zionist regime against Iran, not to burden its case any further," Mullah chiefs sniffed.
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The British Royal Family, operates under a constitutional monarchy, meaning the King does not take any political stance and performs a purely ceremonial role in governing Britain.
Mr Trump has hit Iran with strikes for 12 consecutive nights - and warned there was more to come.
The UK Government said on Thursday its armed forces were ready to protect the country from any attack after Iran's Revolutionary Guards issued a warning over allowing U.S. bombers to fly from UK bases.
"Our Armed Forces are ready to keep the United Kingdom safe from any kind of attacks, whether it's on our soil or from abroad. The UK stands ready 24/7 to defend itself," a Government spokesperson said.
"This includes through operating a layered approach to air and missile defence, provided by Royal Navy, British Army and Royal Air Force assets equipped with a range of advanced capabilities, working closely with our NATO allies," they added.
Extra F-35 and F-16 fighter jets have been now deployed and refuelling tanker planes have landed in Israel ahead of America's next move.
Earlier today, Mr Trump said he was planning a "massive attack which was bigger than ever before".
"I am close to making a decision. We're all set for it," the Commander-in-Chief told Axios.
Face-to-face with the extraordinary threat from Iran, the UK Government said: "Our Armed Forces are ready to keep the United Kingdom safe from any kind of attacks, whether it’s on our soil or from abroad. The UK stands ready 24/7 to defend itself.
