Secretary of Defense James Mattis greets Marine Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, after arriving at the Pentagon on Saturday. (Photo by Air Force Tech. Sgt. Brigitte N. Brantley/ Defense Department)

Newly sworn-in Defense Secretary James N. Mattis quietly arrived at the Pentagon for the first time in his new role Saturday, stepping out of a black sport utility vehicle at noon before entering the building and getting to work.

Mattis, wearing a gray suit and dark overcoat, was greeted by Gen. Joseph F. Dunford, the chairman of the Joint Chiefs of Staff, as they shared a handshake and laugh. The two men have known each other for years, serving together as senior Marine Corps officers before Mattis retired as the four-star chief of U.S. Central Command in 2013.

Mattis and Dunford ascended a staircase at the Pentagon overlooking the Potomac River and Washington. Mattis offered no response when asked by assembled media what is first on his agenda.

The majority of the Pentagon was empty and dark, although a few dozen tourists walked the grounds before his arrival. Most of them were dressed in red and blue paraphernalia showing support for newly sworn-in President Trump, while hundreds of thousands of people demonstrated against Trump across the river in the Women’s March on Washington.

Inside the Pentagon, Mattis held what the Defense Department called a “Top 4” meeting that also included Dunford, Deputy Defense Secretary Robert O. Work and Air Force Gen. Paul Selva, vice chairman of the Joint Chiefs. The Pentagon did not immediately release any details about the gathering.

Defense Secretary James N. Mattis meets with, from left, Air Force Gen. Paul Selva, Marine Gen. Joseph F. Dunford and Deputy Defense Secretary Robert O. Work on Saturday at the Pentagon.. (Photo by Air Force Tech. Sgt. Brigitte N. Brantley/ Defense Department)

Defense officials said they do not expect Mattis to announce any policy changes Saturday. On Friday night, after his nomination was accepted by the Senate and signed by Trump, Mattis released an initial message to Defense Department personnel that said both they and those working in U.S. intelligence are “sentinels and guardians of our nation” — a message that is in line with the new secretary’s past statements, but which contrasts repeated remarks from Trump, who has questioned the value of U.S. intelligence in recent weeks.

Mattis also promised to work to strengthen U.S. alliances abroad, some of which have been rattled by Trump questioning their worth.

“Every action we take will be designed to ensure our military is ready to fight today and in the future,” Mattis said. “Recognizing that no nation is secure without friends, we will work with the State Department, to strengthen our alliances. Further, we are devoted to gaining full value from every taxpayer dollar spent on defense, thereby earning the trust of Congress and the American people.”

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