US Secretary of State Antony Blinken met with two senior Israeli officials Monday and voiced worry over recent deadly strikes by Israel in the Gaza Strip, his spokesman said.

The Israeli army has launched several deadly attacks in recent days including on a refugee camp and a UN-run school that was being used as a shelter. In response, Hamas said it was pulling out of ceasefire negotiations, causing prospects for a truce and hostage release deal to dwindle.

Blinken received Israeli Strategic Affairs Minister Ron Dermer and National Security Adviser Tzachi Hanegbi “to express our serious concern about the recent civilian casualties in Gaza,” State Department spokesman Matthew Miller told reporters.

On Saturday, Israeli strikes killed more than 90 people in the Al-Mawasi camp near Khan Yunis, Gaza’s Hamas-run health ministry said. In May, the camp was declared a safe humanitarian zone by the Israeli military, which told civilians to evacuate to it.

Israel said it had been targeting Hamas military commander Mohammed Deif, one of Israel’s most wanted men for decades, and Rafa Salama, the Islamist movement’s commander in Khan Yunis, believed by Israel to be one of the masterminds of the October 7 attack that triggered the current war.

A Hamas official said Sunday that Deif was “well and directly overseeing” operations, though doubts remained. The two Israeli officials told Blinken that “they do not have certainty yet” about Deif’s fate, according to Miller.

The discussions also focused on a ceasefire between Israel and Hamas, humanitarian aid for Gaza and post-war plans, he said.

The visit comes several few days before Israeli Prime Minister Benjamin Netanyahu is expected to address the US Congress on July 24.

“We continue to hear from Israel directly that they want to reach a ceasefire and that they’re committed to the proposal that they put forward,” Miller said.

The United States has strongly defended Israel’s right to defend itself after the October 7 attacks by Hamas, in which 1,195 people, mostly civilians, were killed, according to an AFP tally based on Israeli figures.

During the attack, Hamas militants also seized 251 hostages, 116 of whom are still in Gaza including 42 the military says are dead.

But Biden has been under mounting political pressure over the plight of Palestinians in the Gaza Strip.

Israel’s military offensive has killed at least 38,584 people, also mostly civilians, according to data provided by the Gaza health ministry.