When he returned to power last year, Trump was eager to negotiate a new deal with Tehran, but a diplomatic breakthrough has been elusive

Trump has threatened to attack Iran, prompting Tehran to warn of retaliation amid growing fears of conflict.

US president adopts more measured tone and suggests a pause in decision on threatened US military action in Iran

From Venezuela and Iran, Trump has attacked countries in the past when diplomacy appeared to be working.

There were growing signs that US military action on Iran might be imminent, then the US president suddenly changed his tune.

When he returned to power last year, Trump was eager to negotiate a new deal with Tehran, but a diplomatic breakthrough has been elusive