Iran on Saturday rejected any modification of its nuclear deal with world powers after US President Donald Trump demanded tough new measures to keep the agreement alive.

Iran “will not accept any amendments in this agreement, be it now or in the future, and it will not allow any other issues to be linked to the JCPOA”, the foreign ministry said in a statement, using the 2015 deal’s technical name.

It has the backing of all the partners to the agreement apart from the United States, with Russia warning Washington that withdrawing would be “a big miscalculation”.

Foreign Minister Mohammad Javad Zarif has said Trump’s aggressive stance on the deal and Iran generally have also violated the commitment to “refrain from any policy specifically intended to directly and adversely affect the normalisation of trade and economic relations with Iran” in the accord.

Responding to Trump’s speech late Friday, Zarif tweeted: “Rather than repeating tired rhetoric, US must bring itself into full compliance — just like Iran.”