Manhattan congressional candidate Jack Schlossberg says he supports the effort to block arms sales to Israel and claims that the US has already lost the war in Iran.

The grandson of President John F. Kennedy said during a recent candidates forum at the Stephen Wise Synagogue on the Upper West Side that he supports the resolutions advanced by far-left Vermont Sen. Bernie Sanders to deny Israel $440 million in bombs and military equipment.

Forty Democratic senators voted for the ban on equipment, but seven Dems sided with Republicans to defeat the measure — including New York Sens. Chuck Schumer and Kirsten Gillibrand.

A second measure, which sought to block the sale of 1,000-pound bombs to Israel, was defeated by a greater margin, 36 votes in favor and 63 against.

“I would have voted with 85% of Democrats to block those funds to Israel,” said Schlossberg, who is running in the Democratic primary for the 12th House District to replace retiring Rep. Jerrold Nadler.

Schlossberg said his position was tied to his opposition to the US-Israel war against Iran, which he claims does not increase security for Americans or Israelis.

“Opposing that war means opposing all funding for that war,” Schlossberg, 33, told the synagogue’s senior rabbi, Ammi Hirsch, who moderated the forum.

“I cannot understand how we continue funding this war which we basically just lost in the Middle East,” he said.

Schlossberg said he still supports Iron Dome funding to help defend Israel from attacks and supports its status as a Jewish nation.

Candidate Nina Schwalbe said she also supported a US ban on selling weaponry to Israel.

“The destruction in Gaza is unacceptable. I’m ashamed America has supported it,” she said.

But other candidates vying for Nadler’s seat told the audience that they backed the US military aid to Israel and opposed the Sanders-proposed blockade.

“I don’t believe it would have actually improved the lives of people on the ground, and it would have contributed to the status of Israel as a pariah state — and I will not do that in Congress,” said state Assemblyman Micah Lasher, a leading candidate backed by Nadler and many West Side Democratic leaders.

Candidate and Trump basher George Conway also said he opposed the resolutions.

Another candidate, state Assemblyman Alex Bores, did not attend the debate.

The Middle East is a political hot potato. House District 12 encompassing the east and west sides of Manhattan has a big Jewish population that supports Israel but also many progressives who support the Palestinian cause or turned against the Jewish state over its military actions in Gaza and Iran.