Washington  - US President Barack Obama last month offered a halt to the US-planned missile defence system opposed by Moscow if Iran could be convinced to relinquish nuclear weapons and ballistic missiles, The New York Times reported on its website Tuesday.

Citing US officials speaking on condition of anonymity, the Times reported that Obama sent a secret letter three weeks ago to Russian President Dmitri Medvedev.

The offer was described as offering Russia an incentive to help the US and other Western powers achieve a halt to any Iranian programmes that could lead to military nuclear capabilities and long-range delivery systems for warheads.

If the Iranian threat were removed, the US could forego the missile defence system, the letter was described as saying.

The Times quoted a senior administration official as saying: "It's almost saying to them, put up or shut up. It's not that the Russians get to say, 'We'll try and therefore you have to suspend.' It says the threat has to go away."

Russia Foreign Minister Sergei Lavrov is to meet Friday in Geneva with US Secretary of State Hillary Rodham Clinton, ahead of an Obama-Medvedev meeting on on April 2 in London. (dpa)