Sen. Cory Booker, D-N.J., accused Mike Waltz of displaying "profound cowardice" at the former national security advisor's confirmation hearing to represent the U.S. at the U.N. Tuesday, amid questions about the Signal group chat that his team had set up to discuss strikes against the Houthis in March.Booker, who refused to ask any questions, said Waltz failed to take accountability when other lawmakers on the Senate Foreign Relations Committee asked him about what has been called "Signalgate."While members of the Trump administration have said no classified information was disclosed in the chat, which mistakenly included a journalist, Democrats have claimed that certain details were classified and jeopardized the safety of the troops involved in the strikes."It compounds what I think is disqualifying about you for this position. It also, to me, just shows profound cowardice," Booker said. "You should step up right now.""I just watched with great disappointment that even after weeks, if not months of reflection, you couldn't sit before this committee and take some responsibility and talk constructively about what's learned," Booker said.Waltz faced questions earlier from Sens. Chris Coons, D-Conn, and Tim Kaine, D-Va., on his involvement in the group chat, where a journalist from the Atlantic was included along with other top administration officials such as Vice President JD Vance,Secretary of State Marco Rubio and Secretary of Defense Pete Hegseth.SENATE DEMOCRATS PREDICTING BRUTAL UN AMBASSADOR CONFIRMATION HEARING FOR MIKE WALTZDuring their questioning, Waltz maintained that no classified information was shared in the group chat, and said no disciplinary action was taken following a White House investigation. The Pentagons inspector generals investigation is currently ongoing."I have nothing but deep disappointment in what I consider a failure of leadership on your part. God, America needs now more than ever forget the partisanship just people to step up and show heart and integrity and honor," Booker said. "When you lie, defer, deflect, demean and degrade journalists, to me it's absolutely unacceptable. I have no questions. I cannot support your nomination. I think you've shown a failure of leadership at a time that America especially needs people of honor to stand up and show what leadership actually is."Waltz, who before his time at the National Security Council previously served as a U.S. congressman from Florida and is a retired Army National Guard colonel and former Green Beret, challenged Bookers statement.NEXT US NATIONAL SECURITY ADVISOR? HERE'S WHOM TRUMP MIGHT PICK TO REPLACE WALTZ"I appreciate the men and women that I've had to lead in combat," Waltz said. "And I think the last thing they would call me is a coward."Waltz and Hegseth both faced scrutiny for their involvement in the Signal chat that Waltzs team created, where members of the Trump administration discussed strike plans against the Houthis.In March, Waltz claimed he bore "full responsibility" for the Signal group chat, and the Trump administration has historically maintained no classified information was shared over the chats. The Atlantic published the full exchange of messages, which revealed that Hegseth included certain attack details such as specific aircraft and times of the strikes.President Donald Trump announced Waltz's departure from heading up the National Security Council at the White House on May 1, and hours later announced the former Florida congressmans nomination to represent the U.S. at the U.N.Waltz could not be reached for comment by Fox News Digital.MIKE WALTZ, OTHER NATIONAL SECURITY COUNCIL STAFFERS OUT IN LATEST TRUMP PURGE FOLLOWING SIGNAL CHAT LEAK