Their brief encounter, on the fringes of this Baltic city's 300th birthday party, will see both men try to gloss over the dispute, and seek to reinvigorate their friendship, analysts say.

Little progress is expected on substantive issues, like the fate of billions of dollars in Russian oil contracts in Iraq, and US concern over Moscow's aid to Iran's nuclear program.

Bush's trip to Saint Petersburg, seen in Washington as a symbolic statement of support for Putin, will not disguise suspicions that as an ex-superpower, Moscow has slipped well down the list of US foreign policy priorities.

The US president, pilloried for once saying he had looked Putin in the eye and was "able to get a sense of his soul," has been criticised by some analysts for not garnering sufficient payback from his relationship with Russia.

Bush makes no apologies for befriending the former KGB agent, whom be met briefly at an official dinner here Saturday night.

"Vladimir Putin and I do have a good relationship," Bush told European journalists before leaving home.

"That is an important beginning in order to make sure the relationship is positive throughout our respective governments.

"If we had a poisonous relationship, it would be awfully difficult to convince others in our governments to work closely together."

Despite vigorously opposing the US war on Iraq, Russia has been spared the scorn poured by Washington on France and Germany.

"We have the strong sense that Russia wants to put our differences over Iraq behind us, that Russia was not comfortable with where it found itself," said a senior administration official on condition of anonymity late Thursday.

Another official appeared to suggest before leaving Washington that Putin would be forgiven for his Iraq stance.

"It is a complicated country, and we are realists about Russia and the political forces within Russia," the official said.

Bush, analysts say, realises the importance of his visit to St Petersburg, on what is a showcase occasion for Putin, who 300 years on is using Tsar Peter the Great's "window on the West" for its founder's purpose.

"This is going to be another in this stage I think for mending the fences and showing in fact that in this instance the US cares," said Fiona Hill, an analyst with the Brookings Institution in Washington.

"But overall, I think we should keep expectations low for the summit."

Rumors in Washington suggest that another Putin-Bush summit could take place in Russia later this year and is more likely to produce more concrete results.

One area in which Moscow can prove its relevance to the United States is in orbit, where its rocket launches to the international space station have taken on added importance since the Columbia space shuttle disaster grounded NASA launches.

Of most pressing concern to Washington in the current relationship is Moscow's involvement with Tehran's nuclear program, as a US confrontation heats up with the Islamic Republic, which Bush has dubbed part of an "axis of evil."

Both sides have found common ground in the US anti-terror campaign, though some human rights activists accuse Washington of overlooking Russian excesses against separatists in Chechnya to ensure Moscow's cooperation.

Bush and Putin will follow up their talks on Sunday with a joint press appearance.

The Russian leader is likely to be less abrasive than during a recent news conference with British Prime Minister Tony Blair in which he pilloried the US-led coalition's failure to find weapons of mass destruction in Iraq.

After they meet the press, Bush and Putin will both travel onto Evian in France for the Group of Eight summit of industrial nations.

Bush leaves Europe on Monday to launch his maiden Middle East peace mission in Egypt and Jordan.

SPACE.WIRE