WASHINGTON — Secretary of State John Kerry said Friday that the nuclear accord he negotiated with Iran was in Israel’s interest and that the Israeli government’s decision to oppose it could further its isolation.

“I fear that what could happen is if Congress were to overturn it, our friends in Israel could actually wind up being more isolated and more blamed,” Mr. Kerry said in an appearance at the Council on Foreign Relations.

There was no immediate response from Israeli officials to Mr. Kerry’s comments, which he made before meeting with American Jewish leaders in New York. But a number of foreign policy experts said that they risked aggravating the tense relations between the Obama administration and Israel.

“It is the kind of statement that would be far more compelling to Israelis, or many in the Jewish community, if it came from an Israeli raising questions about the government’s approach,” said Dennis B. Ross, a former negotiator and senior adviser to President Obama on the Middle East. “I am afraid it will have the opposite effect of what the secretary may have intended.”