DAMASCUS, Syria - The presidents of Syria and Lebanon announced today that Syrian troops will pull back to Lebanon's eastern Bekaa Valley by March 31, but a complete troop withdrawal will be deferred until later negotiations.

The announcement, made after a meeting between Syrian President Bashar Assad and Lebanese President Emile Lahoud, said Syrian troops will pull back from northern and central Lebanon to the east, near Syria's border.

Then, military officials from both countries will decide within a month how many Syrian troops will remain in the Bekaa Valley and how long they will stay there.

After a negotiated timeframe, the two governments will "agree to complete the withdrawal of the remaining forces," the statement said.

The agreement did not set a specific timetable for that complete withdrawal, which could fall short of international demands that Syria completely pull its troops from its eastern neighbor.

However, it stated, "The Syrian and Lebanese agree on continuing the withdrawal of Syrian Arab forces."

Later, journalists saw two Syrian military trucks loaded with furniture heading east up the Lebanese mountains in the first sign of a pullback.

In Lebanon, more than 30,000 ardent protesters gathered at a central square to continue weeks of demands that Syria leave.

Today's meeting came amid intense U.S.-led international pressure on Syria to withdraw its army from Lebanon and to stop interfering in its smaller neighbor's affairs.

Syria has had troops in Lebanon since 1976, when they were sent as peacekeepers during that country's 1975-1990 civil war. When the war ended, the troops remained while Syria dominated Lebanon's politics.

During today's meeting, Lahoud thanked Assad for Syria's role in helping prevent Lebanon's partition after the civil war and expressed "appreciation for the sacrifices made by the Syrian army in Lebanon," Lebanese presidential spokesman Rafik Shalala said.

Lahoud stressed "the unity of the Lebanese-Syrian position in confronting the challenges" and on continuing cooperation, Shalala said.

The announcement said the redeployment to the Bekaa, with a foothold in the high central mountains, was in line with the 1989 Taif Accord that outlined Syria's withdrawal from Lebanon.

That Arab-brokered accord called for Syria to move its troops to the Lebanese border and for both countries to then negotiate the withdrawal.

In Washington, the Syrian ambassador to the United States, Imad Moustapha, told CNN that Syria will withdraw all its troops from Lebanon within a few months. The withdrawal will be done in two stages, he said.

"We entered Lebanon to end a bloody civil war," Moustapha said. "Now we are withdrawing in compliance with international law. We are giving a good example to the rest of the Middle East."