US President George W Bush is returning to Washington at the end of a five-day tour designed to ease strained relations between Europe and the US.
Bush and Putin agreed Iran should not have nuclear weapons
The whistle-stop visit took in Belgium, Germany and Slovakia, as Mr Bush met a series of EU and Nato leaders.
Among the highlights were talks with French President Jacques Chirac, German Chancellor Gerhard Schroeder and Russian President Vladimir Putin.
Commentators say the trip was a success but some key issues remain unresolved.
Agree to disagree
Mr Bush used Thursday's meeting with Mr Putin in the Slovak capital Bratislava to express his "concerns" about Russian democracy.
The two leaders also discussed Russia's nuclear co-operation with Iran - which the US fears is trying to develop a nuclear weapons programme - and Russian arms sales to Syria.
President Bush raised "concerns" over Russian democracy
Speaking after the talks, Mr Bush said they had agreed Iran should not have nuclear weapons.
Mr Putin stressed that Russia had chosen democracy "independently", and not because of outside pressure.
In his speech to Slovaks, the US president praised the 1989 "Velvet Revolution" that defeated communism in the then Czechoslovakia.
On Wednesday, Mr Bush met Mr Schroeder in Mainz, Germany, for talks in which they united in warning Iran not to develop nuclear weapons.
But the two leaders agreed it was best to not to focus on areas of disagreement, such as Europe's desire to lift an embargo on selling arms to China.
Mr Bush had spent the first day of his European visit making strenuous efforts to heal divisions over the US-led war in Iraq and promote transatlantic unity.
On Tuesday, he was rewarded with a pledge from EU and Nato members that they would assist with the reconstruction of Iraq.