James Mattis is on his way out: Trump officials say the Secretary of Defense is leaving the administration

Donald Trump's decision to pull the United States out of Syria may signal an impending exit for Defense Secretary James Mattis, those close to the White House warned.

The Washington Post reported that "Mattis has been repeatedly overruled by Trump in recent months and left out of key discussions as the president pursues his own national security path."

The defense secretary may have reached a "low point" in his influence over the president, current and former administration officials told the Post -- and may become a "short-timer" like so many other Trump administration aides.

Government officials also told the newspaper that Trump "sidestepped Mattis’s concern about deploying U.S. forces to the U.S.-Mexico border this fall with only a vague mandate for border security."

In discussion with Pentagon leaders on the deployment, Mattis said he is "following orders" and instructed them to do the same.