Barack Obama challenges critics of landmark Iran nuclear deal

Barack Obama has launched an aggressive defence of the landmark Iranian nuclear deal, rejecting the idea that it leaves Tehran on the brink of a bomb and arguing the only alternative to the diplomatic accord is war.

The US president vigorously challenged his critics during a lengthy White House news conference after Iran, America and five other world powers finalised a historic, years-long agreement to curb Tehran’s nuclear programme in exchange for billions in sanctions relief.