The White House is preparing to replace H.R. McMaster as national security adviser as early as next month in a move orchestrated by chief of staff John Kelly and Defense Secretary James Mattis, according to five people familiar with the discussions. 

The move would be the latest in a long string of staff shakeups at the White House over the past year and comes after months of strained relations between the president and McMaster. 

A leading candidate to become President Donald Trump’s third national security adviser is the auto industry executive Stephen Biegun, according to the officials.