US President Donald Trump has threatened to trigger a “snapback” of international sanctions against Iran after suffering a “humiliating defeat” at the United Nations security council on Friday.

He told reporters on Saturday: “We’ll be doing a snapback. You’ll be watching it next week,” after a motion to extend a UN arms embargo on Iran was rejected.

Mr Trump said it was unlikely that he would attend an emergency summit of world leaders, called by Russian President Vladimir Putin, to avoid “confrontation” after the threat.