Israeli Prime Minister Benjamin Netanyahu has approved plans for a military assault in Rafah, his office said Friday. The statement did not disclose any specifics about the offensive, which is opposed by several world leaders and humanitarian organizations who believe it may be devastating for the more than 1.4 million Palestinians estimated to be seeking safety in the city.

Secretary of State Antony Blinken told reporters in Vienna on Friday that the Biden administration has not heard a plan from Israel indicating how it would safeguard civilians if the IDF moved into the heavily populated city. President Biden warned earlier this month that an Israeli attack on Rafah would cross a “red line,” though he maintained, “I’m never going to leave Israel.”

White House National Security Council spokesman John Kirby said at a news conference the same day that the United States cannot support an offensive in Rafah that “doesn’t also include a credible, achievable, executable plan to take care of the safety and security” of Gazans there, and an operation without such a plan would “be a disaster.”

Israel Defense Forces spokesman Daniel Hagari said Thursday that the Israeli military aims to send a “significant” section of Rafah’s inhabitants toward “humanitarian islands” in central Gaza that will be built with the “international community.”

Israel also said Friday that it will send a delegation to Qatar to continue discussions for the release of Hamas-held captives in return for Israeli-held Palestinian inmates. The action comes in the wake of the latest cease-fire plan put out by Hamas, which Israel has accused of making “unrealistic demands.”

Kirby said Friday that the Hamas plan was “in broad brushstrokes, within the bounds of the deal that we’ve been working on now for several months.”