K. T. McFarland has been asked to step down as deputy National Security Advisor to President Donald Trump after less than three months and will become U.S. ambassador to Singapore, according to a person familiar with White House personnel moves.

The departure of the 65-year-old former Fox News commentator comes as Trump’s second National Security Advisor, Lt General H.R. McMaster, puts his own stamp on the National Security Council after taking over in February following the firing of Michael Flynn.