US President Donald Trump on Thursday removed National Security Adviser Mike Waltz and appointed Secretary of State Marco Rubio as interim replacement, marking the first major shakeup in his administration since taking office in January. Trump announced the move on his Truth Social platform, saying Waltz would be nominated as the next US ambassador to the United Nations. “He has worked hard to put our nation's interests first,” Trump wrote. Rubio, who now becomes the first person since Henry Kissinger to hold both the Secretary of State and National Security Adviser roles simultaneously, was praised by Trump at a White House event earlier in the day. “When I have a problem, I call up Marco. He gets it solved,” Trump said as per a report by Reuters. Trump had planned to wait until the 100-day mark of his term before dismissing a cabinet-level official, the same report quoted sources as saying. State Department spokesperson Tammy Bruce reportedly learned about the change from reporters during a press briefing. Waltz, a retired Army Green Beret and former Republican congressman, had faced internal criticism, particularly after being linked to a March scandal involving a Signal chat among senior Trump national security aides. He was also blamed for mistakenly adding a journalist from The Atlantic to a private thread that discussed an impending US strike in Yemen — which the magazine later reported. His deputy, Alex Wong, a North Korea expert, is also being forced out, according to reports. The dismissal comes amid a broader purge within the national security ranks. Since April 1, at least 20 National Security Council staffers, the NSA director, and three senior Pentagon political appointees have been dismissed, Reuters reported. Caught using Signal - Again! Photographs from Trump’s Wednesday cabinet meeting have sparked fresh concerns over secure communications, showing top White House officials using a customised version of the Signal messaging app—weeks after a major security lapse involving the platform. One image captured by Reuters shows former national security adviser Mike Waltz using an app labelled TM SGNL during the April 30 meeting. His screen reveals active chats with Vice-President JD Vance, Secretary of State Marco Rubio—now also serving as acting national security adviser—Intelligence Chief Tulsi Gabbard, and Middle East envoy Steve Witkoff. The app in question, TM SGNL, is reportedly a modified version of Signal developed by a company called TeleMessage, The Guardian reported, pointing that the app clones messaging platforms while enabling message archiving, a feature designed to meet presidential record-keeping laws. However, tech experts warn this modification may weaken Signal’s core security, the report mentioned. As 404 Media reported, the archiving feature likely means Signal’s end-to-end encryption “is possibly ‘not maintained, because the messages can be later retrieved after being stored somewhere else.’” One message visible on Waltz’s screen read, “there is time,” apparently directed to Rubio. Another from Vance said: “I have confirmation from my counterpart it’s turned off. He is going to be here in …” There were also signs of a Signal call with Gabbard, and Waltz’s calendar showed a morning appointment marked “PDB”—typically short for President’s Daily Brief.
