First major reshuffle in Trump's team: Homeland Security Advisor Mike Waltz falls victim to "Signalgate" and leaves for the UN

In the first major move in Donald Trump's team since his return to power, the US president on Thursday dismissed his national security adviser, Mike Waltz, who has been weakened by the affair of the military plans being accidentally shared, and intends to make him his ambassador to the UN.

"I am pleased to announce that I will nominate Mike Waltz as the United States Ambassador to the United Nations," Donald Trump wrote on his social network Truth, confirming the departure of his advisor, who held a strategic position, announced a little earlier by the American press.

"From the battlefield in uniform to his role as National Security Advisor to Congress, Mike Waltz has worked hard to put our nation's interests first. I know he will do the same in his new role," the Republican president added.

His Secretary of State , Marco Rubio, will assume the role of national security adviser on an interim basis , he said.

Donald Trump offered no explanation for his decision. But Mike Waltz had been under pressure since late March, when a reporter for The Atlantic magazine exposed a major security breach by revealing that he had been inadvertently added to a group chat on the Signal messaging service about imminent US strikes against Houthi rebels in Yemen.

"Now, Hegseth"

The replacement of the 51-year-old former Republican congressman from Florida is the first major move within Donald Trump's inner circle since his return to the White House about 100 days ago. His first term was rocked by numerous changes among his staff.

Will this replacement remain isolated or could it be the prelude to other changes?

Defense Secretary Pete Hegseth, also a member of the incriminated chat group, in which he shared the timing of planned US airstrikes, is in the Democrats' crosshairs. "Now, Hegseth's turn," pointed out Senate Democratic leader Chuck Schumer on X.

Former Fox News anchor Pete Hegseth is the subject of an internal Pentagon investigation into the matter.

Interviewed by Fox News early Thursday morning, Mike Waltz gave no sign of his imminent departure when he welcomed the agreement on the exploitation of natural resources signed between the United States and Ukraine.

"Nobody thought it could be done. President Trump said, 'Do it!'" he even praised. The former congressman turned presidential advisor was also present the day before at the last cabinet meeting.

He had taken "responsibility" for "Signalgate"

A former US Army Special Forces officer, he took "responsibility" for the leaked military plans in Yemen, explaining that he had created the group on Signal. It included members of the Trump administration, including Hegseth and Vice President J.D. Vance, as well as other senior US officials, such as the heads of intelligence and the CIA. The real-time timeline of the US attacks was shared there.

After the "Signalgate" revelation , Donald Trump had publicly and repeatedly displayed his support for those around him involved in the conversation.

Steve Witkoff, whom the Republican president has made his emissary for negotiations with Russia , on the one hand, and Iran and its nuclear program, on the other, is well placed to succeed Mike Waltz, according to the American press.

In the United States, the White House National Security Advisor plays a major role in defining foreign policy, alongside the Secretary of State.

Four people had held the position during the New York billionaire's first term . Waltz's appointment will need to be ratified by the Senate before he can become the next U.S. ambassador to the UN.