WASHINGTON (Reuters) - Retired U.S. military officers, members of Congress and former U.S. ambassadors were among 52 U.S. national security experts who signed a letter released on Monday urging President Donald Trump’s administration not to jeopardize the international nuclear deal with Iran.

Trump faces deadlines related to the deal starting late this week, including deciding whether to reimpose oil sanctions lifted under the 2015 agreement. He will make the decision as Iran’s government deals with protests over economic hardships and corruption.

Signers of the letter, organized by the National Coalition to Prevent an Iranian Nuclear Weapon, included Richard Lugar, a former Republican chairman of the Senate Foreign Relations Committee; Paul O’Neill, who served as Treasury secretary under Republican President George W. Bush; Michael Hayden, former director of the National Security Agency and Central Intelligence Agency, and Admiral Eric Olson, former commander of Special Forces.

“We support the rights of Iranian citizens to free speech and peaceful protest and we condemn the use of force against peaceful demonstrations,” the letter said.

“In responding to developments in Iran, now and in the future, the U.S. should be careful not to take any steps that might undermine the JCPOA (nuclear agreement) which remains vital to U.S. national security,” it said.