Active-duty Army Lt. Gen. H.R. McMaster, the outspoken White House national security adviser, has reportedly fallen out of favor with President Donald Trump and could lose his job as the president's top in-house consultant on military and foreign affairs.

The White House is considering easing McMaster out and sending him back to military service, possibly with a promotion to four-star rank, CNN reported Thursday, citing several anonymous White House and Pentagon sources.

At a Pentagon briefing Thursday, Dana White, the chief Pentagon spokesperson, deflected questions back to the White House on McMaster's status while noting his distinguished career in uniform.

"General McMaster works for President Trump. Any decisions with regard to the staff -- the White House will make those determinations," she said.

When asked if the military would welcome McMaster back and find a spot for him in the Pentagon's upper echelons, White again deferred to Trump.

"General McMaster is serving the president of the United States. Any decision with respect to any changes" will be up to the White House, she said.

A recent public statement from Trump via Twitter showed daylight between the president and his national security adviser, however.

Trump signaled his displeasure with McMaster last week in a Tweet taking him to task over remarks to a security conference in Munich attended by Defense Secretary Jim Mattis.

McMaster said there is "incontrovertible" evidence that Russia meddled in the 2016 U.S. presidential election. He spoke after Special Counsel Robert Mueller filed indictments against 13 Russians for conspiring to influence the election, partly to favor Trump over Hillary Clinton.

Trump then dressed down McMaster, saying in a Tweet, "General McMaster forgot to say that the results of the 2016 election were not impacted or changed by the Russians and that the only Collusion was between Russia and Crooked H, the DNC and the Dems."

The tweet used Trump’s nickname for his former presidential rival Hillary Clinton and referenced the Democratic National Committee.

However, White House Press Secretary Sarah Huckabee Sanders said Tuesday that Trump "still has confidence in General McMaster."

McMaster has previously been the target of conservative activists who questioned his loyalty to the Trump agenda. He also reportedly clashed with former White House chief strategist Steve Bannon, who himself was ousted by Trump last summer.

In his nomination hearings, McMaster needed a waiver from the Senate to continue on active duty in the White House post. Any move to send him back to the Defense Department, possibly at four-star rank, could present Mattis and Joint Chiefs Chairman Gen. Joseph Dunford with the problem of finding a suitable position for him.

McMaster's well-known penchant for putting his opinions on policy and strategy in blunt terms has often put him at odds with superiors -- in the military and now at the White House.

As a colonel, McMaster, who earned a Silver Star during the Gulf War as a tank commander with Eagle Troop of the 2nd Armored Cavalry Regiment, was initially passed over for promotion to the rank of brigadier general, but his career reportedly was salvaged by the intervention of then-Gen. David Petraeus.

Other top officers have praised him, while noting that his directness can sometimes be grating.

When he was promoted to lieutenant general, retired Army Lt. Gen. David Barno, who had commanded U.S. forces in Afghanistan, said, "H.R. is also the rarest of soldiers -- one who has repeatedly bucked the system and survived to join its senior ranks."

Herbert Raymond McMaster graduated from the U.S. Military Academy at West Point in 1984 and received a Ph.d in American history.

He later expanded his doctoral thesis into a best-selling book that took on the highest-ranking officers in the military over what he perceived as their failures to tell the truth to then-Defense Secretary Robert McNamara during the Vietnam war.

McMaster's thoughts were summed up in the title of the book: "Dereliction of Duty: Lyndon Johnson, Robert McNamara, The Joint Chiefs of Staff, and the Lies that Led to Vietnam."

If McMaster were removed, the White House would be in the position of naming its third national security adviser in little more than a year.

Retired Army Gen. Michael Flynn, Trump's first national security adviser, was forced to resign after admitting that he lied to Vice President Mike Pence about his contacts with Russians.

-- Richard Sisk can be reached at Richard.Sisk@Military.com.