Senators overseeing the military request an investigation at the Pentagon into use of the Signal app

WASHINGTON (AP) - The top Republican and Democrat on the Senate Armed Services Committee requested an investigation Thursday into how Trump national security officials used the Signal app to discuss military strikes, ensuring at least some bipartisan scrutiny on an episode President Donald Trump has dismissed as frivolous.

Sen. Roger Wicker, the Republican chair of the committee, and Sen. Jack Reed, the top Democrat, signed onto a letter to the acting inspector general at the Department of Defense for an inquiry into the potential "use of unclassified networks to discuss sensitive and classified information, as well as the sharing of such information with those who do not have proper clearance and need to know."

The senators’ assertion that classified information was potentially shared was notable, especially after Trump’s Republican administration has contended there was no classified information on the Signal chain that had included Jeffrey Goldberg, editor-in-chief of The Atlantic magazine. In Congress, most Republicans seemed content to allow the controversy to blow over, while Democrats have slammed it as a reckless violation of secrecy that could have put service members at risk.

Asked by a reporter on Wednesday about the call by Wicker, of Mississippi, and Reed, of Rhode Island, for an inspector general probe, Trump replied, "It doesn't bother me."

Wicker, one of the most ardent defense hawks in Congress, has also said the committee will request a classified hearing with a top administration official, as well as for the administration to verify the contents of the Signal chat, which were published by The Atlantic. The contents show that Defense Secretary Pete Hegseth listed weapons systems and a timeline for the attack on Iran-backed Houthi rebels in Yemen earlier this month.

The White House National Security Council has also said it would investigate the matter. White House press secretary Karoline Leavitt told reporters on Thursday that she had no update on the status of that investigation.

"We've been incredibly transparent about this entire situation, and we will continue to be," Leavitt said.

Leavitt is one of three Trump administration officials who face a lawsuit from The Associated Press on First and Fifth Amendment grounds. The AP says the three are punishing the news agency for editorial decisions they oppose. The White House says the AP is not following an executive order to refer to the Gulf of Mexico as the Gulf of America.