US Senate votes to restrain Trump from attacking Iran

The US Senate has voted to restrain President Donald Trump from attacking Iran, with eight members of his Republican Party bucking their leadership to agree.

The resolution, which requires Trump to seek explicit authorisation from Congress before further hostilities with Iran, passed in similar form in the Democratic-led House of Representatives.

But it faces a near-certain veto from Trump after it goes back through the House.

The resolution passed 55-45, with eight Republicans joining the Democrats. The resolution asks the president to go to Congress for explicit authorization to attack Iran, but makes an exception for defending against an "imminent" threat.