The United States and Europe increased pressure on Syria yesterday, demanding Damascus remove its 14,000 troops from Lebanon.
President Bush branded Syria an "oppressive neighbour" to Lebanon and insisted it "end its occupation".
At around the same time, Syria indicated only that it would start withdrawing some of its troops from Lebanon soon.
International and Lebanese pressure has mounted on Syria since the assassination of former prime minister Rafik al-Hariri in Beirut a week ago, blamed by Lebanon's opposition on Syria.
Arab League chief Mr Amr Moussa said President Bashar al-Assad had told him Syria would soon take steps towards withdrawing in line with the Taif agreement, which ended Lebanon's 1975-90 civil war.
"President Bashar al-Assad stressed more than once in [ our] talks his firm intention to press ahead with the implementation of the Taif agreement and to plan a Syrian withdrawal from Lebanon in line with this agreement," he told reporters after meeting Mr Assad in Damascus.
"The issue of Taif and the withdrawal is ... part of Syrian policy. There will be talk and steps that we will see soon," Mr Moussa said.
The 1989 Taif agreement committed Syria to shifting its 14,000 troops in Lebanon to the eastern Bekaa Valley. It also stipulated that Syria and Lebanon should agree a timetable for a complete Syrian pull-out.
Syria, which has 14,000 troops in Lebanon, pulled out or redeployed a few thousand troops last year. It was widely expected to pull out some more troops ahead of a general election in Lebanon, due to take place by May.
"Just as the Syrian regime must take stronger action to stop those who support violence and subversion in Iraq and must end its support for terrorist groups seeking to destroy the hope of peace between Israelis and Palestinians, Syria must also end its occupation of Lebanon," Mr Bush said in a speech in Belgium.
"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," he said at the start of a trip to meet European Union and NATO leaders.
Dr Sami Baroudi, associate professor of political science at the Lebanese American University, said Mr Bush's comments were part of the pressure on Syria to implement last year's UN Security Council resolution calling for it to quit Lebanon.
"I'm sure more messages will be sent at the Brussels summit, but the Syrians don't feel this is the right time to make a 180-degree turn in their policy," Dr Baroudi said.
Lebanon's pound was stable yesterday but the central bank continued to sell dollars amid worries over the death of Hariri, credited with masterminding Lebanon's reconstruction effort.
Although the EU is also pressing for a Syrian withdrawal from Lebanon, it favours more of an "engagement" approach. It joined calls from the US and France for an international investigation into Hariri's killing.
"[ The EU Council] calls for an international investigation without delay to shed light on the circumstances and those responsible for this attack," an EU communique said.
Syria has denied any involvement in Hariri's death and Mr Assad told Mr Moussa he welcomed a UN investigation, announced last week.
Syria has been a dominant player in Lebanon since the civil war and took much of the credit for quelling the violence.
The EU communique also underlined support for a UN resolution that calls for Syria to withdraw all its troops from Lebanon.
British Foreign Secretary Mr Jack Straw told reporters that Europe and Washington saw eye-to-eye over Damascus and that he hoped Lebanon would heed calls for an international probe into the murder of Hariri.