"Both yesterday and the day before, the WHO team was not permitted to enter the hospital to assess the conditions of the patients and critical medical needs, despite reaching the hospital compound to deliver fuel alongside partners," said Tedros Adhanom Ghebreyesus in a statement.
He noted that there are still about 200 patients in the hospital, with at least 20 of them needing urgent referral to other hospitals for healthcare.
"Medical referral is every patient’s right. The cost of delays will be paid by patients’ lives. Access to the patients and hospital should be facilitated," he added.
Nasser Hospital, now defunct, was the largest active medical facility in Gaza and the latest one in dozens of medical complexes targeted by Israel. Gaza’s second-largest hospital has been put "completely out of service," according to a spokesperson for the Gaza health ministry.
"There are only four medical staffers currently caring for patients" inside the Nasser Hospital in Khan Younis, spokesperson Ashraf al-Qidra told Reuters.
On Saturday, Israeli soldiers detained hospital administrators and health personnel, among others, as they continued their weeks-long siege of the hospital—the last one functioning in southern Gaza. Israel has killed hundreds of medical personnel and bombed hospitals and ambulances during its war on Gaza.