Dhaka, May 2 -- US President Donald Trump's National Security Advisor Mike Waltz is to leave his post following a scandal in which a journalist was accidentally included on a chat between officials about air strikes on Yemen, US media reported.

The former US congressman is the first major official to leave the administration in Trump's second term, which has so far been more stable in terms of personnel than his first.

A White House official did not confirm the reports, saying they "do not want to get ahead of any announcement."

Officials on the chat laid out the attack plan, including the timings that US warplanes would take off to bomb targets in Yemen, with the first texts barely half an hour before they launched.

Defense Secretary...