Those tensions flared into public view again last weekend, when Trump rebuked McMaster for saying that the Justice Department's evidence against 13 Russians indicted for election meddling was "incontrovertible".
"General McMaster works for President Trump".
"As you can see with the Federal Bureau of Investigation indictment, the evidence is now really incontrovertible and available in the public domain", McMaster said. Still, Republicans familiar with the situation say he's "safe until he's not", and that they don't believe his position is particularly secure.
White House Press Secretary Sarah Huckabee Sanders said earlier this week that Trump "still has confidence in General McMaster".
CNN previously reported that McMaster has been at odds with the President and other cabinet officials over the previous year.
Several courts have blocked the ban from coming into force while lawsuits against it are pending. Others accuse Steve Bannon of poisoning the well after McMaster removed Bannon from the National Security Council, setting off a vicious smear campaign that's played out on Breitbart News.
Another possible option would be to name McMaster as the replacement for Gen. John Nicholson who has served as commander of the coalition in Afghanistan since 2016.
The Pentagon is considering whether there are any four-star general positions available as a way for Mr. McMaster to leave the White House without creating issues.
Politico said the White House did not immediately respond to a request for comment.
The defense secretary was scheduled to brief the president Wednesday, but the meeting was postponed and will occur soon, officials said, speaking on the condition of anonymity to discuss policy deliberations. Some defense officials caution that the President could also go as far as not to offer him a fourth star and force him to retire.
Even after Bannon was ejected from the White House, McMaster has struggled to find his footing.