Speaking after talks at his family retreat in Kennnebunkport, Maine, Bush said he and Putin recognised the need to "send a common message" to Iran regarding its ongoing uranium enrichment programme, the BBC reported. The United States has accused Iran of seeking nuclear arms, which Iran denies.

But the two leaders failed to resolve differences over the United States’ planned anti-nuclear missile defence shield in Poland and the Czech Republic, the agency said.

Russia has strongly opposed US plans to base parts of the proposed anti-missile shield near Russia’s borders, and recently warned it might target its nuclear missiles towards Europe again. Moscow has also baulked at US-led drives at the United Nations to impose tougher sanctions against Iran for pursuing its uranium enrichment programme.

Talking to reporters after what officials had billed as a casual meeting after a morining fishing trip, the two leaders projected a united front towards dealing with Iran.

"We’re close on recognising that we got to work together to send a common message," said Bush as quoted by the BBC.

Putin said he and Bush would "continue to be successful" in tackling the issue of Iran’s nuclear programme through the UN.

On the vexing question of US plans for a missile defence system in Eastern Europe, President Putin brought a range of new proposals.

These included modernising a radar station in Azerbaijan, which he had previously suggested as an alternative site to Poland and the Czech Republic, and including in the programme a new radar facility being built in southern Russia.

"The relationship of our two countries would be raised to an entirely new level," the BBC reported Putin as saying. He also suggested including more European nations in the decision-making process.