PARIS - French President-elect Nicolas Sarkozy got back to work Thursday after a controversial Mediterranean vacation, meeting with Jacques Chirac and backing calls for an international tribunal to probe the assassination of Lebanon's former prime minister.

Looking tanned after the 2 1/2-day yacht getaway, Sarkozy joined Chirac in leading a poignant ceremony in the capital's Luxembourg Gardens honoring victims of slavery.

The two then hosted the son of assassinated Lebanese leader Rafik Hariri in the presidential palace. Many expect France's relations with the Arab world to cool with the departure of Chirac, who was a close friend of Hariri and supporter of Lebanon, formerly a French protectorate.

But Hariri's son, Saad, told reporters after the meeting that Sarkozy pledged to "continue the relations between Lebanon and France in the same manner as in the past with President Chirac." He said Sarkozy backed the idea of an international tribunal to investigate his father's killing.

Sarkozy and Chirac -- one-time allies who have had tense ties in recent years -- did not speak publicly after the meeting.

Sarkozy, a tough-talking former interior minister, defeated Socialist Segolene Royal on a platform calling for tax cuts, free-market reforms, stronger U.S. ties and proposals to weaken labor protections, which have angered many on the left and in rundown housing projects that erupted in riots in 2005. Despite his solid victory, many predict Sarkozy's reform plans will be challenged by street protests and other resistance.

President Bush, speaking to reporters at the Pentagon Thursday, had kind words for Sarkozy, calling him a "very engaging, energetic, smart, capable person."

"We will have our differences, and we will have our agreements, and I'm looking forward to working with him," Bush said. Sarkozy has called for improved French-U.S. relations, but says he would have kept France out of the Iraq war.

France's Constitutional Council officially declared Sarkozy the winner Thursday; he takes office May 16.

About 150 anti-Sarkozy protesters occupied a branch of the University of Paris in the south of the capital on Thursday, said university officials, who decided to temporarily shut down the school after the move. It was expected to reopen Friday.

The National Police said attackers had torched nearly 200 cars overnight across the nation, a fourth straight night of unrest following Sarkozy's victory. That was down from 296 the night before and the post-election peak of 730 Sunday.

Sarkozy gathered early Thursday with lawmakers from his conservative party to plan for next month's legislative elections, which are crucial to implementing his reforms.

The party currently has a large majority in both houses of parliament but must keep it that way if Sarkozy wants to follow through quickly on ambitious plans to cut taxes, reform labor laws and minimize the effect of France's frequent strikes.

Sarkozy then joined Chirac for a poignant ceremony in Paris' Luxembourg Gardens, where Chirac unveiled a chain-like sculpture in honor of victims of slavery, 159 years after France abolished the practice. Chirac announced the national commemoration day last year, soon after the 2005 riots, which raised questions about France's model of integrating minorities and the lingering scars of its colonial past.