WASHINGTON • Defence Secretary James Mattis has given his farewell message to the US armed forces, telling them to "keep the faith in our country" and stand firm alongside allies after he resigned over policy differences with President Donald Trump.
Mr Mattis, who had been seen as a stabilising factor in US defence policy, transferred authority near midnight on Monday to his deputy Patrick Shanahan, a former executive at Boeing.
A retired Marine general, Mr Mattis has often kept away from the spotlight. He did not have any sort of departure ceremony when he left the Pentagon, leaving his farewell memo as his final public remarks as defence secretary.
Historically, departing secretaries have had a major ceremony.
In his brief message, Mr Mattis acknowledged the political turbulence in Washington but called on the US military to stay firm in its mission "to support and defend the Constitution while protecting our way of life".
"Our department is proven to be at its best when the times are most difficult. So keep the faith in our country and hold fast, alongside our allies, aligned against our foes," the outgoing defence chief said.
Last week, Mr Trump said he was replacing Mr Mattis two months earlier than had been expected, a move officials said was driven by Mr Trump's anger at Mr Mattis' resignation letter and its rebuke of the President's foreign policy.
Mr Mattis had resigned abruptly after falling out with Mr Trump, including over surprise decisions to withdraw all US troops from Syria and start planning a drawdown of forces in Afghanistan.
His resignation letter laid bare the growing divide between them, and implicitly criticised the President for failing to value America's closest allies, who fought alongside the United States in both conflicts.
Our department is proven to be at its best when the times are most difficult. So keep the faith in our country and hold fast, alongside our allies, aligned against our foes.
DEFENCE SECRETARY JAMES MATTIS, in his farewell message to US military forces.
Mr Shanahan, best known for his focus on internal Pentagon reform and his private sector experience, was due to take over as Acting Defence Secretary yesterday.
Mr Trump has suggested Mr Shanahan could stay in the role as acting secretary for a considerable amount of time.
Mr Shanahan has served as the deputy secretary of defence since July 2017. Before joining the Pentagon, he spent three decades at Boeing and was the general manager of the 787 Dreamliner passenger jet unit, among other positions.
The Acting Defence Secretary is not expected to break from major Pentagon policies, including a new focus on the military threats from China and Russia, which were outlined in the US National Defence Strategy.
"Mr Shanahan was instrumental in crafting the National Defence Strategy. His ideas, priorities and philosophy are in that document," his spokesman, Army Lieutenant-Colonel Joe Buccino, said.