Minnesota U.S. Rep. Betty McCollum has joined a growing chorus of Democrats calling for Defense Secretary Pete Hegseth to resign following revelations of a second Signal chat used to share U.S. military operations.

McCollum, a 13-term Democrat who represents the Fourth District in Congress, serves as the ranking member of the House Appropriations Subcommittee on Defense.

She previously called for a congressional investigation last month after it became public that Hegseth shared details of strikes in Yemen in a separate Signal chat with top administration officials. The details of that chat became public after a staffer inadvertently included the editor-in-chief of The Atlantic on the chat.

The New York Times reported that Hegseth used a second chat to discuss a strike that included his wife and brother, who works at the defense department.

"My fellow Democrats and I have warned the American people that Mr. Hegseth was grossly unqualified to serve as Secretary of Defense," McCollum said in a statement Monday. "Now in office, it has become clear that not only is Secretary Hegseth completely incompetent, but his actions are jeopardizing the national security of the United States."

Fellow Minnesota DFL Reps. Kelly Morrison and Ilhan Omar called for both Hegseth and National Security Advisor Mike Waltz's resignations back in March. Waltz apparently was the first official to include the Atlantic editor in the text chain.

Minnesota U.S. Sen. Tina Smith, who also called for Hegseth to resign last month, posted to X Monday asking: "when will Republicans finally call for him to be gone."

Some Minnesota Republicans stood by Hegseth after the first Signal chat was revealed. No GOP members of Minnesota's delegation reacted to the news on Monday.

McCollum said if "anyone else in the military did what Secretary Hegseth did, they would be fired immediately, could be dishonorably discharged, and certainly would lose their security clearance."

"Republicans in Congress are failing to do their job to hold oversight hearings into the Secretary's conduct and the conduct of President Trump's national security team," she added. "They must do so immediately – our national security is at risk."

Neither the White House nor Hegseth denied he shared such information in a second chat, instead they focused their responses on what they called the disgruntled workers whom they blamed for leaking to the media and insisting that no classified information had been disclosed.

This report contains information from the Associated Press.