James Mattis, fabled Marine general and newly appointed secretary of defense, wasted no time getting to work after being approved for the role in a near-unanimous 98-1 vote following President Trump’s inauguration on Friday.

Mattis arrived at the Pentagon on Saturday morning, marking his first visit to the site under his authority, but would not wait for his first full day in the billet before beginning to set the tone for defense operations in the United States. A letter from the Pentagon’s new boss, posted to the Defense Department’s website on Friday night, addresses all employees that fall under Mattis’ purview, and wastes no time in listing a few priorities for the future, some of which could be seen as running counter to statements made by the new president.

In the short letter, Mattis first speaks to the credit of the defense and intelligence communities within the United States, before stating plainly that the agenda of the Defense Department will be to strengthen alliances with friendly nations as well as to make our nation’s defense infrastructure accountable for every dollar it spends.

President Trump has raised concerns around the globe on more than one occasion by suggesting that he may not honor Article 5 of the NATO charter—stipulating that every NATO nation come to the defense of another member nation if attacked—unless other countries begin fulfilling their financial obligations to the alliance.

Mattis, who served as the commander of the Allied Command Transformation within NATO, spoke up in the organization’s defense during his confirmation hearings, saying, “If we did not have NATO today, we would need to create it. It is vital to our national interests, and it’s vital to the security of the United States.”

The other half of Mattis’ objectives, however, align well with the new president. Donald Trump has frequently questioned high-dollar Pentagon initiatives, such as the perpetual problem child, the F35, and he even went so far as to Tweet about canceling America’s “order” for Air Force One due to its cost. Mattis, it would seem, also intends to reign in defense spending, or at least account for it in such a manner as to leave no room for questioning. A common saying in the consulting business states, “All that matters is what can survive an audit,” and Mattis seems to have just such a mentality in mind.

You can read Mattis’ letter to his staff in full below.

It’s good to be back and I’m grateful to serve alongside you as secretary of defense.