A powerful branch of Iran’s military has vowed to defy Donald Trump and the United States by accelerating its ballistic missile programme.

The Islamic Revolutionary Guard Corps (IRGC), an elite national guard force suspected of driving Iranian activities in Iraq, Syria and regions bordering Israel, denounced what it termed the “featherbrained US President”.

The IRGC said it would “keep trying to enhance its regional influence and boost Iran’s missile capabilities incessantly and with more acceleration”, the Tasnim news agency reported on Thursday.

Last week Mr Trump said Tehran was not complying with the spirit of a nuclear deal signed in 2015 under his predecessor, Barack Obama, signalling a more hostile approach that deeply angered Iran.

His move did not take the US out of the agreement but leaves it to Congress to vote on whether to reintroduce sanctions.

Israel and some US politicians have been lobbying to designate the IRGC a terrorist organisation, but Mr Trump did not take that step last week.

Britain, France and Germany – which also were parties to the 2015 deal – said they remained committed to preserving the agreement.

Security officials were quoted on Thursday in Der Tagesspiegel, a Berlin newspaper, as saying Iran was seeking supplies from Germany to build rockets that could be used to mount nuclear warheads.