US President George W Bush has said that the world is speaking with one voice in its calls for Syria to end its political influence over Lebanon.
Syrian troops have been in Lebanon since 1976
Mr Bush backed calls by Secretary of State Condoleezza Rice and French Foreign Minister Michel Barnier for Damascus to withdraw its troops.
Ms Rice said on Tuesday that Syria was endangering peace and frustrating regional peoples' aspirations.
Syria's president says troops could be withdrawn from Lebanon within months.
Bashar al-Assad told Time magazine that this would depend on the security situation in Lebanon and Syria's own security concerns being met.
Strongest pressure yet
Speaking at an event in the US state of Maryland, Mr Bush said the world was "speaking with one voice when it comes to making sure that democracy has a chance to flourish in Lebanon".
Military intervention begins in 1976
30,000 troops in Lebanon during 1980s, currently 15,000
Syrian forces crucial in ending the Lebanese civil war in 1990 and maintaining peace
Calls for departure of the Syrians increase gradually with Israeli withdrawal in 2000
UN resolution calling for withdrawal of all foreign forces passed in Sept 2004
"Both of them stood up and said loud and clear to Syria: 'You get your troops and your secret services out of Lebanon so that good democracy has a chance to flourish,'" he said, referring to Ms Rice's and Mr Barnier's joint news conference on Tuesday.
Correspondents say Mr Bush's words amount to Washington's strongest pressure yet on Syria.
Russia has also cautiously backed the call, saying that UN Security Council resolution 1559, requiring Syrian troop withdrawal from Lebanon, should be implemented.
"We all have to make sure that this withdrawal does not violate the very fragile balance which we still have in Lebanon, which is a very difficult country ethnically," Foreign Minister Sergei Lavrov told the BBC's Newsnight programme.
Speaking after talks in London on Tuesday aimed at showing world support for the Palestinian Authority, Ms Rice called for Lebanon to be free from "contaminating influences".
She said there was "a long list of concerns about a Syria that is standing in the way of Lebanese, Iraqis, Palestinians and others in their aspirations for a better world".
Syria's territory was also being used to support the insurgency in Iraq, she said.
The Lebanese cabinet resigned on Monday, two weeks after the killing of the country's former Prime Minister, Rafik Hariri.
Both the outgoing government and the Syrian government have been accused of involvement in the 14 February assassination of Hariri - charges they deny.
The opposition in Lebanon is expected to decide later on Wednesday whether it will participate in talks with President Emile Lahoud before he chooses a new prime minister.
The opposition leader, Walid Jumblatt, has already called on President Lahoud to resign as well.
The Newsnight interview with Sergei Lavrov will be broadcast on BBC2 at 2230 GMT on Wednesday.