"They've been on the ground for four months, the word we're getting is they're tired, they need to be refit," National Security Council spokesman John Kirby told ABC's "This Week," though he stressed that it was "hard to know exactly what this tells us right now."

Kirby spoke hours after Israel, which has been under increasing pressure from Washington over the conflict's spiralling death toll, pulled all its troops out of southern Gaza, including from the city of Khan Younis, according to the military and Israeli media.

The Israeli Army said a "significant force" will continue to operate in the rest of Gaza, which it invaded after October 7.

At least 33,175 people have been killed in the Palestinian territory in Israel's campaign, according to Gaza's health ministry.

Kirby said he would let the IDF "speak to their operations."

"As we understand it, and through their public announcements, it is just about rest and refit for these troops that have been on the ground for four months and not necessarily, that we can tell, indicative of some coming new operation for these troops," he said.