Trump says national security advisor doesn't need to apologise after journalist was added into group text discussing war plans

Donald Trump said national security advisor Mike Waltz is "doing his best" and denied he should apologise after a journalist was inadvertently added to a group chat discussing plans for military strikes on Yemen.

Top members discussing detailed and sensitive information on messaging app Signal accidentally included a reporter from The Atlantic, sparking questions over how senior Trump officials allowed an outside person in the chat.

Trump told reporters the information revealed on the 18-person group chat, which included Vice President JD Vance and defense secretary Pete Hegseth, was not "classified" and defended Waltz over the snafu.

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"I don't think he should apologise. I think he's doing his best," the president said.

"It's equipment and technology that's not perfect and probably he won't be using it again, at least not in the very near future."

The Atlantic editor-in-chief Jeffrey Goldberg said in an article titled "The Trump administration texted me its war plans" he was added to the chat on March 15 and saw detailed plans to bomb Houthi targets in Yemen.

Goldberg said he was added to the chat on Signal by an account using Waltz's name.

"The plan included precise information about weapons packages, targets, and timing," Goldberg said.

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Trump said the incident had led to his administration limiting its use of Signal.

The president also questioned if the app had security flaws which would allow someone to enter a chat uninvited.

Waltz, meanwhile, said officials would be looking into the matter.

"Of course, we're going to keep everything as secure as possible," Waltz said. 

"No one in your national security team would ever put anyone in danger."

"This one in particular I've never met, don't know, never communicated with," Waltz added of Goldberg.

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"And we're looking into and reviewing how the heck he got into this room."

Hegseth later told reporters that "nobody was texting war plans" when asked about the incident.

The defence secretary also took a swipe at Goldberg, who he described as "deceitful and highly discredited".

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