WASHINGTON (JTA) — Israel’s ambassador to Israel warned against “leaders” who would return the United States to the 2015 Iran nuclear deal.

Ron Dermer apparently was referring to Democratic presidential candidates who have said they would re-enter the agreement.

“There are leaders who are calling to return to that deal,” Dermer said Sunday, speaking to the annual conference of the American Israel Public Affairs Committee. He called that “unacceptable.”

Dermer appeared to be referring to a report last week that identified five Democrats of the 16 or so running who said they would rejoin the deal, which traded sanctions relief for a rollback in Iran’s nuclear program. Three of the five are senators who are seen as viable candidates: Bernie Sanders of Vermont, Elizabeth Warren of Massachusetts and Kamala Harris of California.

Dermer said his proudest moment as ambassador was helping to organize the speech that Prime Minister Benjamin Netanyahu delivered to Congress in 2015 lambasting the then-emerging deal, which he said would accelerate Iran’s acquisition of a nuclear weapon rather than slow it down.

The speech, seen as a rebuke to President Barack Obama, alienated Democrats and exacerbated tensions among the party, Israel’s government and AIPAC, which vigorously lobbied against the deal.

Dermer said President Donald Trump’s decision last year to pull out of the deal was the “most important” of his presidency. He also decried Western major powers who are remaining in the deal.

“We have to get others to walk away,” he said.