The United Nations has brokered an agreement to enable the reconstruction the Gaza Strip, giving a lead role to the Palestinian Authority while involving the private sector, the U.N.'s top Mideast envoy said Tuesday.

The agreement between Israel, the Palestinian Authority and the United Nations includes U.N. monitoring to ensure that construction materials will not be diverted from civilian to military uses, Robert Serry told the U.N. Security Council.

The brutal Gaza war left more than 2,100 Palestinians dead, the majority of them civilians, according to Palestinian and U.N. officials. Israel says the number of militants killed was much higher and accuses Hamas of using civilians as human shields. On the Israeli side, 66 soldiers and six civilians were killed.

Serry said he witnessed "truly shocking levels of destruction to infrastructure, hospitals and schools" during a visit to Gaza last week.

Large neighborhoods have been totally ruined, an estimated 18,000 houses were destroyed or severely damaged, he said. Some 100,000 people have lost their homes, "leaving families shattered and despairing." He said 111 U.N. facilities were damaged and over 65,000 displaced Palestinians are still living in U.N. shelters.

"The Gaza conflict is an appalling human tragedy, and has also exacted a terrible cost in already strained trust," Serry said. "While the cease-fire brokered by Egypt has largely held since Aug. 16, it remains worryingly fragile with the underlying dynamics still unaddressed."

He said the United Nations considers the "temporary mechanism" to rebuild Gaza "a signal of hope to the people of Gaza" and an important step toward lifting all remaining closures of crossings into the Strip. He stressed that it "must get up and running without delay."

Serry called on the Security Council to support the agreement, saying it will help give donors confidence that what they investing in "will be implemented expeditiously, and solely for their intended civilian purpose."