Bolton vows to 'squeeze' Iran

US National Security Advisor John Bolton yesterday vowed to "squeeze" Iran "until the pips squeak", a week after a tough new round of sanctions came into force.

President Donald Trump has dramatically increased pressure on Tehran, withdrawing from an international agreement aimed at ending its nuclear programme and slapping several rounds of unilateral US sanctions.

The latest tranche of measures have been touted as the toughest yet, and aim to significantly reduce Iran's vital oil exports and cut off its banks from international finance.

Speaking in Singapore ahead of a summit, Bolton said: "We think the government is under real pressure and it's our intention to squeeze them very hard.

"As the British say, squeeze them until the pips squeak. We are going to significantly increase the enforcement of sanctions."

The US measures have been opposed by other parties to the deal aimed at ending Iran's nuclear drive -- Britain, France, Germany, China and Russia -- who have vowed to keep the accord alive.

UN inspectors say Iran is abiding by the accord. US is demanding that Tehran end policies rooted in the 1979 Islamist revolution, including its support for regional proxies and its development of missiles.