WASHINGTON

US Sen. Jim Risch said Tuesday that there will be an investigation into senior Trump officials who reportedly shared classified material in a Signal chat, the Hill website reported.

Risch, the chair of the Senate Foreign Relations Committee, said he spoke to Secretary of State Marco Rubio “at length" after National Security Advisor Mike Waltz mistakenly disclosed classified plans to attack Yemen’s Houthis by adding The Atlantic magazine's Editor-in-Chief Jeffrey Goldberg to a chat with top officials using the commercially available Signal app.

"This is a matter that’s going to be investigated, obviously, we’re going to know a lot more about it as the facts role out," Risch was quoted by the Hill.

“But from the State Department standpoint, I can assure you there was no one at the State Department was aware at all there was the leakage that was going on," the Republican senator added.

Goldberg said in his bombshell report that he had been mistakenly added to the group of senior officials on the Signal messaging platform on March 13 after receiving a connection request from an account bearing the name of Waltz two days prior. Alongside him in the group were accounts bearing the names of Waltz, Rubio, Defense Secretary Pete Hegseth, Director of National Intelligence Tulsi Gabbard and Stephen Miller, a top aide to Trump.

Hegseth claimed Monday that "nobody was texting war plans" in his first comments since the growing scandal became known, and called Goldberg a "deceitful and highly discredited so-called journalist who's made a profession of peddling hoaxes time and time again."

President Donald Trump, for his part, stood in lockstep Tuesday with his advisor, saying Waltz "has learned a lesson, and he’s a good man".

Goldberg pushed back Monday on Hegseth’s remarks. "That's a lie."He was texting war plans," Goldberg told CNN.

Goldberg said Tuesday he could be open to sharing more details from the group.

"Maybe in the coming days, I’ll be able to say okay I have a plan to have this material vetted publicly,” Goldberg told the Bulwark website. "But I’m not going to say that now."

Democrats demand resignation of officials

Several Democrats, including Mark Warner, the top Democrat on the Senate Intelligence Committee, demanded senior officials resign.

"When the stakes are this high, incompetence is not an option. Pete Hegseth should resign. Mike Waltz should resign," Warner said on X.

The lawmakers blasted the incident as a "breach" of US national security, and called for a full investigation.

"Every single senator, Democrat and Republican and independent, must demand accountability. I am calling for a bipartisan investigation in the Senate of this mishandling," Senate Minority Leader Chuck Schumer said from the Senate floor Tuesday.

Calling it a "serious matter," Schumer said the Senate as well as all relevant authorities within the executive branch must investigate it "fully."

"We need to know how this conversation was allowed to happen in the first place on an unsecure channel. We need to know the potential damage it could have caused our national security," he said.

The fifth-ranking House Democrat Ted Lieu urged the resignation of Hegseth.

"His reckless actions endangered lives of American troops, endangered our national security, and makes it so that our allies don’t want to share sensitive classified information with us anymore," Lieu told reporters Tuesday.

House Speaker Mike Johnson said the White House is looking into how the other number was "inadvertently" added.

"Obviously, that was a mistake and a serious one," he said. "They've acknowledged that it was an error and they're correcting it ... I don't think anyone should have lost their job over that."