WASHINGTON - U.S. aid chief Samantha Power arrived in Egypt's Sinai Peninsula on Tuesday, where she is expected to announce more than $21 million in additional assistance for the Palestinian people, a U.S. Agency for International Development (USAID) spokesperson told Reuters.

USAID Administrator Power arrived in Al Arish with a delivery of 36,000 pounds of food assistance and medical supplies airlifted by the Department of Defense from Jordan and intended for Gaza, USAID spokesperson Jessica Jennings said.

The additional assistance that Power will announce on Tuesday will support the provision of hygiene and shelter supplies, food and other assistance for residents of Gaza and the West Bank affected by the Israel-Palestinian conflict.

The funds will also support psychosocial care and critical health services along with the establishment of a NGO-operated field hospital in Gaza that will provide in-patient care.

Only a fraction of Gaza's hospitals remain operational due to Israeli bombing and a lack of fuel, and those still functioning are increasingly overwhelmed by a new wave of wounded arriving.

The Gaza health ministry has said that at least 15,899 Palestinians, 70% of them women or under 18s, have now been killed in Israeli bombardments of the Hamas-ruled enclave in eight weeks of warfare. Thousands more are missing and feared buried in rubble.

Israel launched its assault to wipe out Hamas in retaliation for an Oct. 7 cross-border attack by Hamas gunmen who killed 1,200 people and seized 240 hostages, according to Israeli tallies - the deadliest single day in Israel's 75-year history.

Intense Israeli air strikes hit the south of the Gaza Strip on Monday, killing and wounding dozens of Palestinians, including in areas where Israel had told people to seek shelter, residents and journalists on the ground said.

While in Al Arish, Power will meet with officials and Egyptian and international humanitarian organizations working to speed up assistance into Gaza.

She will raise Washington's commitment to the protection of civilians and the need for humanitarian supplies to exceed the levels reached during the humanitarian pause.

Fighting between Israel and the Hamas Palestinian militant group resumed on Friday after a seven-day pause to exchange hostages and prisoners and deliver humanitarian aid.

U.S. officials, in public and private, have repeatedly urged Israel to minimize civilian casualties in southern Gaza because of the high toll incurred in northern Gaza military operations.

(Reporting by Daphne Psaledakis; Editing by Don Durfee and Stephen Coates)