Vladimir Putin and George W. Bush hold their final summit here Sunday trying to put an amicable face on tense US-Russia ties yet unable to bridge wide gaps on European security and other issues.

Bush arrived in this Russian Black Sea resort late Saturday and was given a tour by Putin of models of planned 2014 Sochi Winter Olympics sites before the two retired to Putin's seaside residence for an informal, private dinner.

The ambience at the dinner, also attended by Russian president-elect Dmitry Medvedev, was described afterwards by White House spokeswoman Dana Perino as "warm, very comfortable, easygoing."

But Bush and Putin were to get down to more serious talks starting at 0600 GMT on Sunday that were expected to touch on their differences over US missile shield plans, NATO expansion, arms treaties and other contentious issues.

Officials from both countries have said that a "strategic framework" document, a joint statement aimed at defining a path forward in US-Russian relations, would be issued at the Sochi talks.

But even as Bush was on his way to Russia from Croatia, where he lauded that country's accession to NATO after generations of Kremlin domination, the White House downplayed talk of a US-Russia breakthrough on the missile defence plan.

"We're going to have to do more work after Sochi," White House spokeswoman Dana Perino told reporters aboard Bush's plane.

"No one has said that everything would be finalised and everyone would be satisfied," she added.

Putin leaves office next month with Bush doing the same eight months later and observers said both leaders would like their relationship to be remembered for more than just the US-Russian disputes that have risen during their terms.

Those disputes however show little sign of being resolved anytime soon, although there have been some indications of movement on the missile defence split that US officials have said they hope Russia will acknowledge at the Sochi talks.

The US missile plan foresees installing nine interceptor missiles in Poland and a radar in the Czech Republic to guard against missile attacks from "rogue states" like Iran.

Russia counters that Iran poses no missile threat to the United States and said it views the shield as a threat to its own security.

The United States said it has made "forward-leaning" concessions to assuage Russia's concerns that include, for example, giving Russian liaison officers access to system sites in Poland and the Czech Republic.

"The Russians said that these were useful and important," US Secretary of State Condoleezza Rice told reporters last week on the sidelines of the NATO summit in Bucharest."

We hope that we can move beyond that to an understanding that we will all have an interest in cooperation on missile defence" during the Bush-Putin meeting in Sochi, she said.

Russia has also warned that NATO membership for ex-Soviet Ukraine and Georgia would be a "serious strategic mistake" that Moscow would take as a direct threat and that would undermine wider European security.

Putin was credited with a big diplomatic coup last week when the NATO summit refused to put Ukraine and Georgia on a formal track for alliance membership, as Moscow wished, despite vigorous pleas from Bush.

But no sooner was that decision announced then 26-nation alliance said it had no doubt that the two states would be taken in later, irking Putin enough that he held an unscheduled news conference at the NATO summit.

In addition to his swansong meeting with Putin, Bush was also scheduled to hold talks with Medvedev, who takes office on May 7.

Medvedev, Putin's hand-picked successor, has signalled that he plans no major departures from the Putin policy line -- a point he has underscored with plans to make Putin his first prime minister.