The United Nations and the Palestinian government called Tuesday for international donors to provide $550 million in aid to help hundreds of thousands of Palestinians affected by a devastating Israeli offensive on Gaza.

The appeal comes two weeks after Israel and Hamas ended 50 days of bloodshed that killed more than 2,100 Palestinians, mostly civilians, and a month ahead of a donors' conference in Cairo.

"The scope of damage and devastation is unprecedented in the Gaza Strip," James Rawley, the UN's humanitarian coordinator for the Palestinian territories, said in a statement.

"The crisis is far from over."

Rawley and Palestinian deputy prime minister Mohammed Mustafa outlined the humanitarian needs for Gaza after the attacks, calling for $551 million (427 million euros) for food aid, access to clean water, healthcare and education.

"We challenge the world to be ambitious and daring in helping us realise recovery, reconstruction and a better future for Gaza," Mustafa said.

"An immediate measure is to end the blockade on Gaza and ensure our people never again experience the horrors of this summer," he said.

Rawley echoed calls for a "full lifting of the blockade."

Israel agreed to ease restrictions on goods entering Gaza under a truce deal reached with Hamas on August 26.

But restrictions remain on building materials, which are crucial for reconstructing the Strip, large residential parts of which were flattened by Israeli artillery and aerial bombardment during the assault.

Israel says steel and concrete could be used by Gaza fighters to make weapons and build tunnels for attacking Israel.

Of the three crossings into the tiny coastal enclave, Israel controls two -- one for personnel movement and another for goods. Egypt controls the third.

Tight restrictions of people movement are enforced, with only some in the Strip allowed to enter and exit, mostly for humanitarian reasons such as emergency medical care.

The UN has predicted that more than 100,000 people are to remain homeless in the long term.

Israel launched its Gaza offensive on July 8, ostensibly in response to rocket fire from Hamas and other Gaza-based resistance groups.

More than 2,100 Palestinians were killed, of which 70 percent were civilians, according to the UN.

On the Israeli side, 67 soldiers and six civilians were killed. Most rockets fired into Israel were intercepted or struck open ground.

*This story was edited by Ahram Online.