Some 30 House Democrats, including members of the so-called “Squad,” are calling on the U.S. State Department to reveal information about Israel’s nuclear program to “pave the way for coherent nonproliferation policy.”

The Jewish state has long been reported to have a nuclear program, but it has historically kept a policy of ambiguity about its nuclear capabilities, neither confirming nor denying possession of nuclear weapons.

Its posture appears to serve as a deterrent to regional adversaries and avoid inspections and other documentation under the the Non-Proliferation Treaty.

Rep. Joaquin Castro (D-Texas), ranking member of the House Foreign Affairs Committee’s Western Hemisphere subcommittee, is leading the effort.

“We cannot develop coherent nonproliferation policy for the Middle East, including with respect to Iran’s civil nuclear program and Saudi Arabia’s civil nuclear ambitions, while maintaining a policy of official silence about the nuclear weapons capabilities of one party central to the ongoing conflict in which the United States is a direct participant,” the signatories wrote to U.S. Secretary of State Marco Rubio.

“We ask that you hold Israel to the same standard of transparency that the United States expects from any other country that may be pursuing or retaining nuclear weapons capability,” they wrote.

The lawmakers noted the number of nuclear-armed countries involved in some form in the Iran war.

“We are, in the fullest sense, fighting this war side-by-side with a country whose potential nuclear weapons program the United States government officially refuses to acknowledge,” the House members wrote.

“Congress has a constitutional responsibility to be fully informed about the nuclear balance in the Middle East, the risk of escalation by any party to this conflict and the administration’s planning and contingencies for such scenarios,” they added. “We do not believe we have received that information.”

The letter asks Rubio for specifics on Israel’s nuclear weapons systems and enrichment capabilities, and whether assessments have taken place to inspect under what parameters Israel would deploy its weapons.

Among those supporting Castro’s effort are anti-Israel House progressives who are part of the so-called “Squad.”