US President George W Bush and Russian leader Vladimir Putin meet at a summit in Germany on Thursday for the first time in half a year as ties between their countries sink to a post-Cold War low.
The two presidents have not met face-to-face since before Putin launched an attack on the Bush administration at a conference in February, where he accused Washington of trying to force its will on the world and become its "single master".
The target of Putin's verbal assault was a missile shield Washington plans to deploy in Poland and the Czech Republic which Moscow says will upset the global strategic balance.
Speaking to reporters on the sidelines of a Group of Eight summit, Bush said Russia did not pose a threat to Europe despite Putin's vow last week to target it if Washington deploys 10 interceptor missiles in Poland and a radar on Czech territory.
"Russia is not going to attack Europe," Bush told reporters at the start of the summit on the Baltic coast.
The Kremlin also played down Putin's comments, saying they were hypothetical and just one option Russia was considering.
Bush has also signaled he would raise concerns that Putin is eroding democratic freedoms in Russia. The Kremlin responded by saying Washington should not meddle in its domestic politics.
Analysts say Russia's relations with the West are at their lowest point since the Cold War.
Washington says the missile shield is intended as a defense against attacks by "rogue" states like Iran and North Korea. Moscow suspects the shield is aimed at Russia and fears it could eventually be outfitted with attack missiles or used for spying.
Bush said he hoped to use the summit and his first bilateral meeting with Putin since November to ease Russian concerns.
Struggle for compromise
Police and protesters clashed near the summit venue on Wednesday, temporarily blocking all roads in and out of the luxury hotel in Heiligendamm where the leaders were gathering.
The missile shield is not the only issue dividing Russia, the United States and fellow G8 members Britain, France, Germany, Italy, Canada and Japan.
Other divisive topics include climate change, aid to Africa and a host of international issues on which they disagree, such as Iran's nuclear program and the future of Kosovo.
Top G8 negotiators, the "sherpas", were working late into the night on Wednesday to try to hammer out a deal that could lead to an agreement on firm targets for greenhouse gas cuts.
"We've still got quite a lot to resolve," said an aide to British Prime Minister Tony Blair.
A senior Bush adviser said Washington opposed setting firm targets for greenhouse gas cuts but offered reassurance that its plan for fighting climate change would not undermine UN efforts to protect the environment.