WASHINGTON (JTA) — An Obama administration official’s anonymous attack on Israeli Prime Minister Benjamin Netanyahu was “disgraceful,” Secretary of State John Kerry said.

“That does not reflect the president, it does not reflect me, it is disgraceful, unacceptable, damaging,” Kerry said Thursday at a symposium organized by The Atlantic magazine, which originally published the slur, and the Aspen Institute.

The official called Netanyahu “chickenshit,” referring specifically to what he said was Netanyahu’s reluctance to confront settlement advocates, but speaking more broadly to anger over differences between the Obama and Netanyahu governments on a potential nuclear deal with Iran.

“They make life much more difficult,” Kerry said, referring to anonymous attacks.

Talking about U.S. military assistance to Israel during its war with Hamas in the Gaza Strip over the summer, the secretary of state said, “We are proud of what we’ve done to help Israel through a very difficult time.”