Washington (CNN) A group of former national security officials and experts are calling on Donald Trump to disclose his overseas business dealings, questioning whether the Republican nominee has conflicts of interest with US foreign policy.

More than 50 past officials signed the letter released Monday, a mix of Democratic and Republican national security leaders.

The letter notes that Trump's business dealings overseas could pose "unprecedented" and "significant conflicts of interest" if he guided US foreign policy. It demands Trump disclose in full what his foreign business interests are, and to promise to divest himself of them if he wins in November.

"Our next commander-in-chief will inherit complex national security threats and complicated relationships with allies and adversaries alike," the officials wrote. "But our policies must be motivated exclusively by what is in America's best interest, not by the financial interests of our president. The onus is on Donald Trump to assure voters that this will be the case by disclosing the nature of his overseas relationships and committing to divest such assets."

Signatories include Hillary Clinton supporters like retired Gen. John Allen and former Defense Undersecretary for Policy Michele Flournoy.

Also signing were a number of former George W. Bush administration officials, including former Homeland Security Secretary Michael Chertoff, former Deputy Defense Secretary Paul Wolfowitz, former national security adviser Robert Blackwill, former Deputy Director of National Intelligence for Analysis Thomas Fingar and former acting CIA Director John E. McLaughlin.

The letter shares some overlap with a missive from a group of 50 GOP national security officials who last month wrote a letter opposing the Republican candidate.

Trump has refused to release his tax returns, saying they are under audit, and has given limited information about his businesses to the public. He has said he will separate himself from the business if he became president, leaving it in charge of his children.

But experts tell CNN putting his children in charge would not do enough to minimize potential conflicts of interest.

Trump has more than a dozen properties all over the world.

The letter was first reported by The New York Times.

The Trump campaign did not immediately respond to a request for comment.