UNITED NATIONS - The UN chief added his voice Sunday to the UN Security Council's call for an immediate end to hostilities in Gaza and urged Israel to allow humanitarian aid into the poverty-stricken territory.

UN Secretary-General Ban Ki-moon "joins the Security Council's call for an immediate stop to all violence and all military activities.

"He deplores that violence is continuing today, and he strongly urges once again an immediate stop to all acts of violence," his spokeswoman Michele Montas said in a statement.

The 15-member UN Security Council earlier Sunday issued a non-binding statement calling for "an immediate halt to all violence" in the Gaza Strip and urged the parties "to stop immediately all military activities."

The statement followed massive Israeli air raids on Gaza on Saturday and Sunday, in retaliation for Palestinian militants' repeated rocket attacks on Israel. The Israeli attacks have so far killed more than 300 people and wounded some 600, medics said.

Ban was "saddened by Palestinian casualties," Montas said, also mentioning eight UNRWA (UN Relief and Works Agency for Palestine Refugees in the Near East) trainees and one UNRWA staff member killed in the raids, "and one Israeli casualty."

"The Secretary-General also expects the Security Council's call for all parties to address the humanitarian and economic needs in Gaza to be fully heeded, in particular for border crossings to be open by Israel for the continuous provision of humanitarian supplies," the spokeswoman said.

Montas said the UN humanitarian coordinator in Gaza received a guarantee from Israeli officials on Sunday that "all required humanitarian supplies and personnel" would be allowed into Gaza.

"The Secretary-General fully expects this cooperation to continue on a rolling basis in the coming days," she added.

Israeli Defense Minister Ehud Barak on Sunday authorized the transfer of more than 100 truckloads of aid into Gaza, his office said.

More than 100 trucks will transfer the goods on Monday through the Karni, Nahal Oz and Kerem Shalom crossings between Israel and the territory ruled by the Islamist movement Hamas, Barak's office said.

"The UN is working actively to promote urgent implementation of the Security Council's calls to end the violence, reopen the crossings and restore calm in full," Montas added.