WATCH: Defense Secretary Austin holds briefing on transition of power following Trump victory

WASHINGTON (AP) — Defense Secretary Lloyd Austin directed the military Thursday to ensure a smooth transition to President-elect Donald Trump, while emphasizing its obligation to follow the lawful orders of the next commander in chief.

Watch Defense Secretary Lloyd Austin’s remarks in the player above.

Although such memos are rare, it was not the first time the military’s top civilian leader urged the force on its duty to the Constitution amid a transition of power under Trump.

However, the Biden administration has taken unusual steps to isolate them amid the new president’s proposal to deploy federal forces to the southern border and Project 2025 plans to expel career civilians and fill positions with Trump loyalists officials and to remind the military of its own oaths.

“The U.S. military will stand ready, as always, to implement the policy decisions of its next commander in chief and to obey all lawful orders from its civilian chain of command,” Austin wrote in his letter to Defense Department employees.

“The U.S. military will continue to stay away from the political arena; to guard our republic with principles and professionalism; and stand with the valued allies and partners who strengthen our security,” he wrote.

Austin reminded all military members that they swore an oath to support and defend the Constitution – “and that is exactly what you will continue to do.”

In 2016, outgoing Obama administration Defense Secretary Ash Carter also pushed for an orderly transition after Trump’s election, telling the force he knew it would continue in the tradition of excellence: “Our citizens know they expect this can.”

And when Trump’s Defense Secretary Jim Mattis resigned in 2018, he called on the force to remain “unimpaired by our sworn mission to support and defend the Constitution.”

“Our department has a proven record of being at its best in the most difficult times,” Mattis wrote in December 2018 after he resigned over disagreements with Trump over a troop withdrawal in Syria.

After the Biden administration issued a new rule in April through the Office of Professional Management to further protect career civil servants from being involuntarily replaced by political appointees, Austin reiterated the Pentagon’s commitment to do the same. In a letter dated July 10, he said officials would be protected “from unlawful or other inappropriate political attacks.”

The regulations were a response to an executive order issued by Trump in 2020 that aimed to allow the reclassification of tens of thousands of the 2.2 million federal workers, reducing their job security protections, which is expected to come back in Trump’s second term will come to fruition. It’s unclear what kind of protections these workers will still have in a new administration, especially if Trump issues an executive order repealing protections for these civilian workers under President Joe Biden.