Vijay Nambiar, U.N. Secretary-General Kofi Annan's special political adviser, came to the besieged Lebanese capital leading a U.N. delegation to explore ways to end the violence shaking Israel and Lebanon.
Hezbollah's capture of two Israeli soldiers last week sparked an Israeli military offensive against Lebanon and Hezbollah rocket attacks on Israel.
Reading from a terse, prepared statement, Nambiar called for the protection of civilians and civilian infrastructure, which he said "must be respected by all parties."
"Enough innocent lives have been lost and property and infrastructure has been damaged," he told reporters after holding talks with Prime Minister Fuad Saniora.
Nambiar said the United Nations supports Saniora, his "call for a cease-fire and his aim of exercising full authority over the entire country." Such calls require deploying the Lebanese army to the south and, implicitly, the disarmament of Hezbollah.
The U.N. envoy also called for the release of the captured "as part of a solution to this conflict."
Annan has said that he was deeply worried by the escalating cross-border fighting between Lebanon and Israel. On Saturday, Saniora called for the U.N. to broker a cease-fire to open the way for diplomacy to end the crisis.
Accompanying Nambiar was Annan's special envoy Terje Roed-Larsen and U.N. Mideast envoy Alvaro de Soto.
Roed-Larsen has extensive experience with Lebanese issues. He participated in talks to draw the border between Lebanon and Israel after its troop withdrawal in 2000 following an 18-year occupation. He is also overseeing implementation of U.N. Resolution 1559 of 2004 that demands the disarmament of Hezbollah and Palestinian guerrillas.
More than 150 Lebanese civilians have died in violence that began following the capture of two Israeli soldiers by Hezbollah militants. Israel intensified its attacks against Lebanon on Thursday, blasting Beirut's airport and two Lebanese army air bases near the Syrian border, and imposing a naval blockade.