Gaza has been under bombardment by the Israeli military since Palestinian militants of Hamas on Oct. 7 killed what Israel says were 1,400 people and took more than 240 captive into Gaza.

"We continue to work in partnership with ... Egypt and Israel towards safe passage for more US citizens, their immediate family members and US lawful permanent residents," State Department deputy spokesperson Vedant Patel said.

There were around 400 American citizens and their family members, totaling around 1,000 people, who wanted to get out, U.S. Secretary of State Antony Blinken said last week.

"This is an ongoing and fluid situation," Patel said on Tuesday. The number of U.S. citizens who will be able to leave is expected to increase, he said.

More than 10,000 people, around 40 percent of them children, have been killed in Israel's bombardment of Gaza, according to health officials there.

At least 320 foreign nationals and dependents passed through the Rafah crossing on Tuesday, the only border crossing not controlled by Israel, along with 100 Egyptians, an Egyptian security source said.

The crossing was closed on Saturday and Sunday after an Israeli strike on an ambulance that was heading to Rafah.

Patel said that as of Tuesday, 526 trucks carrying humanitarian supplies had entered Gaza through the Rafah crossing. The U.S. is working with Israel to develop inspection mechanisms that would allow trucks to move into Gaza quickly, he said.

Egyptian officials have previously said Israeli inspection procedures "significantly delay the arrival of aid".

Both Israel and Hamas have rebuffed calls for a halt in fighting. Israel says hostages should be freed first. Hamas says it will not free them or stop fighting while Gaza is under attack.

Washington has backed Israel's position that a ceasefire would help Hamas militarily, but has called for pauses in the fighting for humanitarian reasons and possible hostage release talks.

(Reporting by Humeyra Pamuk, Daphne Psaledakis and Paul Grant; editing by Grant McCool)