The largest medical facility still managing to function in the wartime Gaza Strip is now a hospital in little more than name only, the head of the World Health Organization said Sunday.

After a week of siege by the Israeli military, there are only about 20 critically ill patients left at Nasser Hospital — but even that is too many for it to handle, said Tedros Adhanom Ghebreyesus, the WHO director-general.

“Nasser hospital in Gaza is not functional anymore,” Tedros said on social media.Tedros said Sunday that some 200 patients remained at the hospital in Khan Younis, in the southern Gaza Strip, and that about 20 of them urgently needed to be transferred elsewhere.

Israel has justified its military actions at the hospital by saying that Hamas militants have been using it and other medical centers to conceal military activities, and Sunday it said it had found both weapons and Hamas militants at the Nasser complex.

Hamas has repeatedly denied using hospitals as cover.Asked about the WHO statement, a spokesperson for the Israeli military, Lt. Col. Richard Hecht, said in a briefing that “it’s in our best interest that the hospital keeps functioning.” He said that work was being done to fix a broken generator there and that a temporary generator was in use.

But the Israeli military also said that its troops were continuing to deploy at Nasser hospital and in nearby areas and that they had uncovered more weapons there.

Tedros said that WHO workers who reached the hospital over the weekend had not been permitted to enter it to assess the conditions of the patients, but he said a fuel delivery was made to the medical facility.

His statement came a day after Israeli Prime Minister Benjamin Netanyahu said that talks to reach a cease-fire and a deal for the release of the hostages taken in the Hamas-led Oct. 7 attack were at an impasse. Netanyahu said his government was pushing ahead with plans for a ground offensive in Rafah, in the southern Gaza Strip, despite mounting international warnings over the humanitarian cost.

With Israel under pressure to suspend its military assault in Gaza, begun after the Hamas-led cross-border attack in October, the Israeli Cabinet met Sunday and approved a resolution rejecting any attempts by the international community to impose a Palestinian state on Israel.

This article originally appeared in The New York Times.