Lebanese military officials say Syria has completed the first phase of its troop withdrawal from Lebanon.

Military sources say Syrian troops and intelligence officers have pulled back to the Bekaa Valley of eastern Lebanon and at least 4,000 soldiers have actually crossed the border to return home to Syria. The officials say this completes the first phase of the troop withdrawal.

The news comes amid growing pressure by Lebanese opposition groups, the United States and European countries for Syria to pull out of Lebanon completely and end its three-decade-old presence there. Despite the present redeployment, Syria still has some 10,000 troops on Lebanese soil.

Simmering resentment over the Syrian presence erupted after the assassination of former Lebanese Prime Minister Rafik Hariri in Beirut one month ago. Lebanese opposition groups accused Syria and the Syrian-backed Lebanese government of involvement and called on the Syrians to leave and the government to resign.

In another development, the leader of Lebanon's Shi'ite Hezbollah organization, Sheikh Hassan Nasrallah has rejected President Bush's call for the militant group to disarm.

In a television interview, Sheikh Nasrallah said his organization needs to be armed to protect Lebanon and deter Israeli aggression.

Sheikh Nasrallah's comments follow suggestions from Mr. Bush that Hezbollah could play a political role in Lebanon if it disarmed and supported the Israeli-Palestinian peace process.

Hezbollah has both a military and political wing. The United States has designated Hezbollah as a terrorist organization and Mr. Bush said that designation remains.