A U.S. diplomat on Tuesday slammed a new report on food security in the Gaza Strip that said famine was “highly likely” in part of the enclave, with the criticism fueling confusion and controversy over a humanitarian crisis that has drawn significant international attention.

The report, released on Monday by the Famine Early Warning Systems Network, a food security initiative known as FEWS Net, cited recent food supply data and population estimates to suggest that northern Gaza, where Israel has renewed its military campaign over the last three months, was reaching famine conditions.

In response, Jack Lew, a diplomat serving as the U.S. ambassador to Israel, said on Tuesday that FEWS Net’s report was “irresponsible” and relied on “outdated and inaccurate” population data, making it a poor predictor of food security issues.

“At a time when inaccurate information is causing confusion and accusations, it is irresponsible to issue a report like this,” Mr. Lew said. “We work day and night with the U.N. and our Israeli partners to meet humanitarian needs‚ which are great.”

The dispute highlights the difficulties with data collection in Gaza that have hampered humanitarian efforts since the war began. Israel’s bombardment of the enclave, which began after a Hamas-led attack on Israel on Oct. 7, 2023, has forced repeated mass displacements and made it extremely difficult for aid groups to track civilians, determine their needs and, critically, gain an understanding of how much shifts in population data may reflect displacements or deaths.

Israel has said that it works hard to facilitate supplies to Gaza but that aid groups have often failed to deliver assistance because of widespread looting and lawlessness. The Biden administration warned Israel in October to let more aid in or face restrictions on military assistance. In November, it said that Israel had made important changes to improve the supply flow but that more still needed to be done.