The supreme leader of Iran has defended the 2015 nuclear deal and used strong language to accuse US President Donald Trump of ranting and lying.

"I don't want to waste time on answering the rants and whoppers of the brute US president," Ayatollah Ali Khamenei said.

Mr Trump has refused to certify to the US Congress that Iran is complying with the terms of the deal.

He has threatened to terminate the Obama-era agreement altogether.

The American leader called for the deal to be amended to prevent Iran from developing nuclear weapons or intercontinental ballistic missiles.