(WASHINGTON) -- President Donald Trump on Tuesday downplayed the use of a Signal group chat among top officials to discuss a U.S. attack on Houthis in Yemen -- brought to light when a journalist, Jeffrey Goldberg of The Atlantic, was "inadvertently" added to the chat.
Trump claimed there "was no classified information as I understand it," when he was peppered with questions on the reported mishap during a meeting with his ambassadors at the White House. Trump came to the defense of national security adviser Michael Waltz and touted the military operation as a success.
"They used an app, if you want to call it an app, that a lot of people use. A lot of people in government use, a lot of people in the media use," Trump said.
Goldberg, the editor-in-chief of The Atlantic, wrote in a piece published Monday that he was added to a group chat in the commercially available Signal app in which officials, including Secretary of Defense Pete Hegseth and Waltz, were discussing impeding strikes on Houthi militants in Yemen. Goldberg said he was apparently added to the chat by Waltz.
The story in The Atlantic only described the operational part of the message chain, but did not divulge specifics.
When asked if anyone would be fired as a result of the firestorm, Trump responded: "We've pretty much looked into it. It's pretty simple, to be honest ... It's just something that can happen. It can happen."
Trump attacked The Atlantic as well as Goldberg and doubled down on the success of the airstrikes.
"Well, I mean, look, we look at everything and, you know, they've made a big deal out of this because we've had two perfect months," Trump said.
Waltz said he had technical experts -- rather than the FBI -- looking into the matter and told Trump, "We're going to keep everything as secure as possible. No one in your national security team would ever put anyone in danger."
The Atlantic pushed back against Trump's claims.
"Attempts to disparage and discredit The Atlantic, our editor, and our reporting follow an obvious playbook by elected officials and others in power who are hostile to journalists and the First Amendment rights of all Americans," the magazine said in a statement Tuesday evening. "Our journalists are continuing to fearlessly and independently report the truth in the public interest.
"Jeffrey Goldberg was the recipient of information about and discussion of military planning among the country’s top national security leaders when he was inadvertently added to their non-secure messaging group," it added. "This is stunning — and was confirmed yesterday by the National Security Council."
Democrats on Capitol Hill sounded off against the administration over the incident throughout Tuesday.
Rep. Seth Moulton, D-Mass., a Marine veteran, said during a news conference that the Signal group chat national security breach "put American lives at risk."
Moulton said Trump administration officials are lying about the incident, which is "not in the leadership manual for our armed services."
"Oh, this information wasn't classified? Without even knowing the full details, we know that the time of attack for this operation was in the message. Let's be clear: That's classified information. That's all you need to know," he added.
The congressman acknowledged that there is "no excuse here but there is also clearly no accountability, and it's very clear that Secretary Hegseth, with how he is handling this, has no honor, has no sense of duty and has absolutely zero accountability for his own actions."
House Minority Leader Hakeem Jeffries called for Hegseth to be fired over the group chat.
"Pete Hegseth is the most unqualified Secretary of Defense in American history," he said in a statement. "His behavior shocks the conscience, risked American lives and likely violated the law."
Earlier Tuesday, Democrats grilled Director of National Intelligence Tulsi Gabbard and CIA Director John Ratcliffe over the use of Signal and the information discussed on the chat.
The intelligence officials, who were testifying as part of a previously scheduled hearing before the Senate Select Committee on Intelligence, also asserted there was no classified information included in the message chain.
Facing questions from Senate Democrats on why information on attack sequencing or timing, as reported by The Atlantic, would not be considered classified, Ratcliffe said Defense Secretary Hegseth had authority to determine what was classified or not. Gabbard deferred such questions to the Defense Department.
Ratcliffe also said he believed national security adviser Waltz intended the chat to be "a mechanism for coordinating between senior level officials, but not a substitute for using high side or classified communications for anything that would be classified."
Democratic Sen. Mark Warner, the vice chairman of the panel, slammed the incident as "sloppy" and said others would have been fired for the same conduct. Warner also pressed officials to share the messages with lawmakers after they said they contained no classified information.
"If there was no classified material, share it with the committee. You can't have it both ways," he said.
Republicans on the panel did not raise as many questions on the issue during the hearing, which had been set to focus on worldwide threats. Though Sen. Todd Young, a Republican of Indiana, said he would be asking questions about the Signal incident in a closed-door session.
Officials with the White House's National Security Council said they "are reviewing" how Goldberg could have been mistakenly added to the 18-member group chat that included several of the nation's top military officials.
Press secretary Karoline Leavitt confirmed the review on Tuesday, but said that "no 'war plans' were discussed." She added that no classified material was sent to Signal group chat.
"The White House Counsel's Office has provided guidance on a number of different platforms for President Trump's top officials to communicate as safely and efficiently as possible," she said.
"At this time, the message thread that was reported appears to be authentic, and we are reviewing how an inadvertent number was added to the chain," NSC spokesperson Brian Hughes said in a statement, which was sent to ABC News after first being published by The Atlantic.
The scope of the review, including whether it would attempt to determine why high-level discussions about military planning were taking place outside of official channels, was not immediately clear from Hughes' statement.
Trump did not commit to changing procedure or cutting off completely the use of Signal within the administration as a result of the fiasco.
"I don't think it's something we're looking forward to using again. We may be forced to use it. You may be in a situation where you need speed as opposed to gross safety, and you may be forced to use it, but, generally speaking, I think we probably won't be using it very much," he said.
Despite his effort to downplay the incident, President Trump repeatedly indicated he does not like this means of communication, saying he thinks it is best to be in the Situation Room for these conversations.
"Sometimes somebody can get onto those things. That's one of the prices you pay when you're not sitting in the Situation Room with no phones on, which is always the best, frankly," Trump said.
"Look, if it was up to me, everybody would be sitting in a room together," Trump later said. "The room would have solid lead walls and ceiling and a lead floor. But, you know, life doesn't always let you do that."
ABC News' Fritz Farrow, Luis Martinez, Lauren Peller, Lalee Ibssa, Isabella Murray, Ivan Pereira and Meredith Deliso contributed to this report.