The US and three major European nations are to postpone moves to refer Iran to the UN Security Council over its nuclear programme, diplomats have said.

The UN nuclear watchdog, the IAEA, is due to meet in Vienna on Thursday.

Iran's parliament voted on Sunday to end co-operation with UN inspectors and press ahead with uranium enrichment if it is referred to the Security Council.

Tehran insists its nuclear programme is for civilian energy only, but the US fears it could be used for weapons.

Diplomats close to the negotiations said Iran would be given more time to consider a compromise that would move the most sensitive part of nuclear fuel production - uranium enrichment - to Russia.

Under the plan, Iran would be allowed to engage in uranium conversion, but Tehran has resisted the proposal since it was first mooted two weeks ago.

Tehran argues that it has a legitimate right to peaceful nuclear technology.