Turkey's foreign minister, Ali Babacan, urged the sides to find the political will "to stop the bloodshed" and pledged his government's support in finding a solution.

"Nobody should tolerate what's going on in Gaza," Babacon said during a visit to Kosovo. "Turkey is actively engaged, actively involved and working closely with Egypt to have a solution as soon as possible."

Much of the diplomacy focuses on an area of southern Gaza just across the Egyptian border that serves as a weapons smuggling route, making Egypt critical to both sides in any deal.

Israel wants smuggling tunnels along the border sealed and monitored as part of any deal, and has been bombing the tunnels throughout the campaign.

The U.N. Security Council has already passed a resolution calling for a cease-fire. Ban was headed to the Mideast on Tuesday to enforce the measure.

Speaking at U.N. headquarters in New York on Monday, Ban said he has been on the phone constantly with top officials in the Middle East, Europe and the United States promoting the cease-fire. But he said phone calls are not a substitute for direct talks with leaders who have influence on the parties.

"To both sides, I say: Just stop, now," the U.N. chief said. "Too many people have died. There has been too much civilian suffering. Too many people, Israelis and Palestinians, live in daily fear of their lives."

The secretary-general said he plans to meet senior officials in Egypt and Jordan on Wednesday, then head to Israel, the West Bank, Turkey, Lebanon, Syria and Kuwait. He has no plans to go to Gaza.

The fighting has raised concerns about a looming humanitarian disaster in Gaza, where hundreds of thousands of people are without power and running water.

The Israeli army said about 100 truckloads of humanitarian aid, including wheat, flour and medical supplies, were expected to be let into the territory on Tuesday. The aid was sent through during a daily three-hour lull that Israel has declared to allow humanitarian supplies to be delivered.

In Brussels, the European Union's aid chief said Tuesday that Israel has not respected international humanitarian aid during the war. EU Commissioner Louis Michel, speaking in a published interview, cited the high number of civilian casualties and difficulties of delivering aid to the needed.

In Oslo, Norway, meanwhile, the head of the U.N. agency for Palestinian refugees, Karen Abu Zayd, urged the Israeli army to do more to allow supplies into the besieged area.

"We are getting a lot of help from the Israeli Defense Forces on the one crossing that's open to get more and more trucks in, but it's just not enough," she said.