Outgoing Secretary of Defense James Mattis issues his final holiday message to US troops

Outgoing Secretary of Defense James Mattis issued a final holiday message to U.S. troops on Christmas Eve "holding the line." The decorated general is set to leave his post at the Pentagon before Jan. 1.

What are the details?

Mattis issued his resignation letter to President Donald Trump last week over foreign policy disagreements, following reports that the commander in chief would be withdrawing all military personnel from Syria. Although Mattis planned to step down at the end of February, the president announced Sunday that Deputy Secretary of Defense Patrick Shanahan would be taking over the top spot starting on the first of the year.

In a video recorded Dec. 19 — one day prior to submitting his resignation letter — Mattis told U.S. troops, "To all you lads and lasses holding the line in 2018, on land, at sea, or in the air, thanks for keeping the faith. Merry Christmas and may God hold you safe."

#SecDef Mattis' final holiday message to the DOD: "To all you lads and lasses holding the line in 2018 on land, at sea, or in the air, thanks for keeping the faith. Merry Christmas and may God hold you safe." pic.twitter.com/YIdMaVgIWE
— Julio Rosas (@Julio_Rosas11) December 24, 2018

On Christmas Eve, the Department of Defense released a letter penned by the secretary of defense, echoing the messaging from his video and again reiterating to "those in the field or at sea, 'keeping watch by night' this holiday season...in this world awash in change, you hold the line."

#SecDef Mattis's Holiday Letter to the Troops pic.twitter.com/xiwcpMpC4q
— U.S. Dept of Defense (@DeptofDefense) December 25, 2018

Anything else?

President Trump took a parting shot at Mattis on Twitter the same day, saying the defense secretary did not share the president's concerns over other countries taking advantage of the United States through military and trade agreements.

....We are substantially subsidizing the Militaries of many VERY rich countries all over the world, while at the same time these countries take total advantage of the U.S., and our TAXPAYERS, on Trade. General Mattis did not see this as a problem. I DO, and it is being fixed!
— Donald J. Trump (@realDonaldTrump) December 24, 2018

Mattis, 48, has served as secretary of defense since January 2017.