As of Sunday, the Palestinian death toll passed 8,000, most of them women and children, according to the Health Ministry in Hamas-ruled Gaza, the Associated Press reported. In the occupied West Bank, more than 110 Palestinians have been killed in violence and Israeli raids.

Several U.S. leaders have called for a pause in fighting to allow for humanitarian aid to reach civilians in Gaza. But on Sunday, Sullivan warned that any pause in fighting would benefit Hamas.

“That’s a reality. There are a lot of complicated realities. A humanitarian pause would be a good thing to get hostages out, but you can bet that Hamas will try to use that time to their advantage as well. These are the things that Israel was trying to grapple with,” Sullivan said, adding the U.S. was pressing Israeli leaders to “make sure to distinguish between Hamas and the Palestinian people who Hamas does not represent.”

Israeli Rear Adm. Daniel Hagari said Israel has sent more troops into the Gaza Strip.

“The ground operations in the northern Gaza Strip continue,” Hagari said. “We are progressing through the stages of the war according to plan. We are gradually expanding the ground activity and the scope of our forces in the Gaza Strip.”

Nahal Toosi contributed to this report.