By John Geddie

TOKYO (Reuters) -The head of the U.N. agency for Palestinian refugees said on Wednesday Israel's model for providing aid to Gaza was wasteful and a "distraction from atrocities", criticising a chaotic distribution by a U.S.-backed foundation this week.

On Tuesday, thousands of Palestinians rushed an aid distribution site set up in the Israeli-held southern Gaza city of Rafah operated by the Gaza Humanitarian Foundation (GHF), with desperation for food overcoming wariness about biometric and other checks Israel said it would employ.

"The model of aid distribution proposed by Israel does not align with core humanitarian principles," UNRWA Commissioner-General Philippe Lazzarini told reporters at the Japan National Press Club in Tokyo.

"We have seen yesterday the shocking images of hungry people pushing against fences, desperate for food. It was chaotic, undignified and unsafe," Lazzarini said.

"I believe it is a waste of resources and a distraction from atrocities," he added, referring to civilian deaths during Israel's air and ground war in the small coastal enclave.

Israel says its military operations target only Hamas-led militants and accuses them of using civilians for cover, which they deny.

As a trickle of aid has resumed, Israeli forces - now in control of wide areas of Gaza - have kept up their offensive, killing 3,901 Palestinians since a short ceasefire collapsed in mid-March, according to the Gaza Health Ministry.

The GHF, backed by Israel and its close ally, the United States, said it had distributed about 8,000 food boxes, equivalent to 462,000 meals, since Israel eased an 11-week-old blockade of the war-shattered Palestinian enclave last week.

The United Nations and other international aid groups have boycotted the foundation, which they say undermines the principle that humanitarian aid should be distributed independently of the parties to a conflict, based on need.

U.S. State Department spokesperson Tammy Bruce dismissed criticism of the aid program as "complaints about style".

Israel says one advantage of the new aid system is the opportunity to screen recipients at designated sites to exclude anyone found to be connected with Hamas. Israel, at war with Hamas since October 2023, accuses Hamas of stealing supplies and using them to entrench its position. Hamas denies this.

(Reporting by John Geddie; editing by Tom Hogue and Mark Heinrich)