Israel's planned military offensive in Rafah, Gaza, will hurt the country's national security, the U.S. State Department warned Tuesday.

"It will leave Israel more isolated in the world. It will separate Israel from countries that have been longtime partners of Israel, and you've heard this from countries all around the world," State Department spokesman Matthew Miller told reporters at a news conference.

He said Washington believes a full-scale operation will cause civilian harm to Palestinians and hinder the flow of humanitarian assistance.

Most of the aid going to the war-ridden Palestinian enclave enters through Rafah.

Miller reiterated that the operation is not in Israel's interest either.

The U.S. opposes Israeli plans to launch a ground attack on Rafah, where more than 1.4 million people have taken refuge from Israel’s ongoing war in the Gaza Strip. Defense Secretary Lloyd Austin urged Israel to protect Palestinians, as he told his Israeli counterpart Yoav Gallant that the protection of Palestinian civilians was a moral and strategic imperative. Austin called the situation in the Gaza Strip a "humanitarian catastrophe" during their meeting on Tuesday.

Israel has waged a deadly military offensive on the Palestinian territory since an Oct. 7 cross-border attack by Hamas which killed less than 1,200 people.

More than 32,400 Palestinians have since been killed and nearly 74,800 injured amid mass destruction and shortages of necessities.

The Israeli war, now on day 172, has pushed 85% of Gaza’s population into internal displacement amid acute shortages of food, clean water and medicine, while 60% of the enclave's infrastructure has been damaged or destroyed, according to the UN.

Israel is accused of genocide at the ICJ, which in January issued an interim ruling that ordered Tel Aviv to stop genocidal acts and take measures to guarantee that humanitarian assistance is provided to civilians in Gaza.