United States and Europe ratcheted up pressure on Syria, joining thousands of Beirut protesters in demanding Damascus remove its 14,000 troops from Lebanon.
US President George W. Bush, in Brussels for the keynote speech of a trip to Europe, branded Syria an "oppressive neighbour" to Lebanon and insisted it "end its occupation".
In Beirut, 15,000 Lebanese protesters echoed his message.
Chanting "Syria out", they marched in protest at last week's killing of former Prime Minister Rafik al-Hariri in a bomb which Lebanon's opposition blamed on Syria.
"The truth is, we can't stand Syria," they chanted.
The 25-nation European Union called for an international probe into Hariri's death and underlined their support for a United Nations resolution calling for Syria to withdraw.
Europe and the United States, at odds over issues that range from the war in Iraq to global warming, see eye-to-eye on how to deal with Damascus, British Foreign Secretary Jack Straw said.
"The whole of the European Union is on exactly the same page as the United States in respect of Syria," Straw told reporters. He added that he hoped Lebanon, which has resisted calls for an international probe, would change its mind.
In Damascus, the head of the Arab League, Amr Moussa, said on Monday that President Bashar al-Assad had assured him in talks that Syria would soon take steps towards a withdrawal, but he did not specify what or when.
Bush talks tough
Anti-Syrian sentiment has risen sharply in Lebanon since a massive bomb killed Hariri and 15 other people on February 14. Many opposition figures and protesters have pointed the finger at Syria, which has denied any involvement.
Long-time opponents of Syria's grip on its tiny neighbour, including a pervasive intelligence presence, have seized on the anger at Hariri's brutal end to escalate their protests.
US pressure has mounted also.
Washington accuses Syria of supporting militants fighting Israel from both Lebanon and the Palestinian territories as well as insurgents fighting US-backed authorities in Iraq.
In Brussels, Bush called for an end of such support, then added: "Syria must also end its occupation of Lebanon."
Bush said before his visit he would press European leaders to join Washington in pressuring Syria.
"Our shared commitment to democratic progress is being tested in Lebanon, a once-thriving country that now suffers under the influence of an oppressive neighbour," Bush said.
Although the EU is also pressing for Syrian withdrawal from Lebanon, it has pursued a policy of engagement towards Damascus.
Despite US objections, the EU initialled a trade and cooperation agreement last year intended to boost ties with Syria but it has yet to sign or implement the accord.
In a communique, EU foreign ministers on Monday called for "an international investigation without delay to shed light on the circumstances and those responsible for this attack (that killed Hariri)."
