By Paul Adams
Diplomatic Correspondent

Publishedduration31 minutes agoimage copyrightEPAimage captionIran's leaders said its policies would not change based on the result of the US presidential election

US President-elect Joe Biden says the international system is "coming apart at the seams".

He's promised to salvage America's reputation and says he's in a hurry. "There will be no time to lose," he wrote in Foreign Affairs magazine earlier this year.

On his long to-do list is a pledge to rejoin the 2015 Iran nuclear deal – the Joint Comprehensive Plan of Action (JCPOA), to give it its formal title – one of the signature, if hotly debated, achievements of Donald Trump's predecessor in the White House, Barack Obama.

Since withdrawing from the deal in May 2018, President Trump has been doing his utmost to demolish it.