Israel's seemingly sudden large-scale military withdrawal from Gaza's south appears to be "largely rest and refit for troops," White House national security spokesman John Kirby said Sunday.

Israel announced Sunday that it had withdrawn all troops save a single brigade from southern Gaza, but offered little elaboration on the reasoning behind the shift.

Appearing on CBS' "Face the Nation" shortly after the announcement, Kirby said that it appeared the shift was a respite to war-weary Israeli troops.

"The indications that we've been getting from them this morning is this is really largely rest and refit for troops that have been on the ground consecutively now for four months," the National Security Council spokesman said. "They need a chance to come out."

"Now, what they'll do with those troops after a rest and refit, I can't speak to."

Kirby reiterated that the U.S. does not support a major Israeli ground operation in the city of Rafah, a notion that has proven a sticking point between the two nations in recent weeks.

Israeli Prime Minister Benjamin Netanyahu has been adamant that such an operation in Rafah is necessary to root out Hamas and end the war that began on Oct. 7 with Hamas' surprise assault on Israel.

President Biden and members of his administration have repeatedly urged Netanyahu against going into Rafah, where displaced Palestinian civilians have gathered en masse amid the advance of Israeli troops.

Israel has faced mounting international pressure to drastically reduce civilian casualties in Gaza and significantly increase access to humanitarian aid.

More than 33,000 Palestinians have been killed in Gaza since the start of the war, according to Gaza's Hamas-run health ministry.

Some 1,200 people were killed in Israel during Hamas' Oct. 7 attack.

In both cases, civilians represent the majority of those killed.