Secretary of State Condoleezza Rice (search) made a surprise visit to volatile Lebanon on Friday to encourage a new democratic government outside Syrian control and better relations between the two Mideast countries.

Hours after Rice left the city, witnesses said an explosion rocked a busy street of restaurants and bars in a Christian neighborhood of Beirut (search).

"We would like to see the day when there are good neighborly relations between Syria and Lebanon based on mutual respect and equality," Rice said at a joint news conference with Lebanese Prime Minister-designate Foud Saniora earlier in the day.

"But good neighbors don't close their borders to their neighbors," she said of tightened Syria security measures that have delayed or stranded thousands of Lebanese vehicles at the two countries' border. "It is a very serious situation on the Lebanon border, where Lebanese trade is being strangled."

The meeting with Saniora was her third stop during an unannounced visit to Lebanon under heavy guard.

Rice met earlier with Saad Hariri (search), son of assassinated former Prime Minister Rafik Hariri. And together, they visited the seaside grave of the elder Hariri, an anti-Syrian politician slain in a February car bombing.

Afterward, she went to the Presidential Palace for a meeting with Lebanon's pro-Syrian President Emile Lahoud, later also having separate meetings with Saniora and pro-Syrian speaker, Nabih Berri.

En route to Beirut, Rice had said that she viewed the stop in Lebanon as "an opportunity first of all to congratulate the Lebanon people on their incredible desire for democracy."

The visit comes three days after formation of a new Cabinet led by Saniora.

"What I'm here to do is to support the new Lebanon," Rice said. "The new Lebanon is one that is democratic; the new Lebanon is one that should be free of foreign influence. It is a Lebanon in which the Lebanese should make decisions for Lebanon."

Rice is the first senior U.S. official to visit Beirut in more than two years. She arrived from Jerusalem, home base for a long weekend of talks with Israeli and Palestinian leaders.

The Lebanese opposition blamed Syria and its agents for Hariri's slaying. And a new government emerged from a season of political change following the assassination.

Hariri's son leads the newly dominate anti-Syrian faction in parliament and Saniora is a protege of his father.

The killing also has been followed by a time of violence and political tensions, including a wave of anti-Syrian activity in which Damascus charges more than 30 Syrians were killed, as well as the assassinations of an anti-Syrian journalist and a politician, which the Lebanese blame on Syria.

This month, Syria started doing border lengthy inspections, delaying cargo trucks departing Lebanon for Syria and bound for other Arab countries.

Many Lebanese speculate that the Syrian measures are retaliation for April's forced withdrawal of thousands of Syrian troops from Lebanon. Syria says the security measures were needed after authorities discovered trucks carrying suspect materials, including one with 200 kilograms of explosives.

On Wednesday, the State Department said it was prepared to work with the new Lebanese government but not with any Hezbollah Cabinet members. The new 24-member parliament includes one member of the militant group the U.S. calls a terrorist organization.

Rice's predecessor, Colin Powell, was the last senior American diplomat to come to Beirut. At the time of his May 2003 visit, Syria was still firmly entrenched as the dominate political and military force in Lebanon.

The United States helped lead international demands that Syria end its three decades of dominance in Lebanon and withdraw its troops.

Rice went to Jerusalem in a hastily arranged visit in an effort to rescue a shaky Mideast truce amid an escalation of violence before Israel's mid-August withdrawal from the Gaza Strip. Her schedule was left loose deliberately so Rice could shuttle between the leaders with last-minute concerns.

Although Rice repeatedly has said the United States would take a back seat as the Israelis and Palestinians work out their differences, her trip was seen as a sign that she planned to keep up the pressure for progress.

The hastily planned trip was Rice's third to Jerusalem and the West Bank since she took over at the State Department in January.