The U.S. Marine who went missing from his post in Iraq and nearly three weeks later turned up safe in Lebanon was returned to the United States yesterday amid continued questions about the circumstances of his disappearance.

Cpl. Wassef Ali Hassoun arrived at Marine Corps Base Quantico in Virginia at 3 p.m. yesterday aboard a C-12 military aircraft from Dover, Del. Hassoun entered the United States earlier in the day after a nine-hour flight from Germany, where he was evaluated by doctors after his reappearance in Beirut last week.

Hassoun, who was born in Lebanon, initially was thought to have deserted his post. Pentagon officials classified him as captured after a videotape surfaced on an Islamic extremist Web site showing Hassoun with a large knife positioned over his head. At one point, there were reports that Hassoun had been beheaded, but an extremist group later said it released Hassoun with the promise that he would not rejoin U.S. forces to fight. Hassoun arrived at the U.S. Embassy in Lebanon days later.

Hassoun has had contact with his family, but neither he nor relatives have publicly disclosed details of the past several weeks. The Pentagon likewise has remained silent about Hassoun's case, which is being handled by the Naval Criminal Investigative Service. It is unclear what he has told military officials since his reappearance.

Marine officials said yesterday that Hassoun will spend the coming weeks at Quantico, where a team will evaluate his condition, debrief him and work to reintegrate him into military life -- a standard repatriation process for every service member who is captured in the field and returned to safety.

Although Hassoun will be made ready to return to full duty, military officials said there will be scrutiny of his story by naval investigators. Sources said the intelligence community is also interested in questioning Hassoun. Marine officials said the repatriation process takes precedence over the work of criminal investigators, which they said will be worked out in time.

Lt. Col. David Lapan, a spokesman for the 2nd Marine Expeditionary Force, told reporters at Quantico's main gate yesterday afternoon that Hassoun "remains in good condition and good spirits." He said repatriation could take weeks or even months. Hassoun will remain on the base and will have a military escort wherever he goes.

Hassoun slept for most of his flight from Germany and greeted a military friend and a former supervisor when he arrived at Dover Air Force Base, smiling and chatting with them before the trip to Quantico. Hassoun, who will have the opportunity to speak with legal advisers while at Quantico, so far has not asked for an attorney, Marine officials said yesterday.

In a prepared statement upon his release from a hospital in Landstuhl, Germany, on Wednesday, Hassoun said only that he was "excited" to be going home and that he was in good health and spirits.

"All thanks and praise are due to God for my safety," he said in the statement, which was released by the Marines.

Hassoun's arrival at Quantico was private, and the Marines released photographs of Hassoun stepping off an airplane. There will be no media interviews for Hassoun while he is at the base, said officials, who added that he will have the opportunity to meet with his family.

Cpl. Wassef Ali Hassoun, front right, is welcomed to Quantico, where he will be questioned about the 19 days he was missing from his post in Iraq.