President Barack Obama on Wednesday huddled with top military commanders, urging a smooth transition of power and praising their respect for civilian rule.

"We have to make sure that during this transition period that there is a seamless passing of the baton," Obama said in remarks before a closed-door meeting with his Joint Chiefs of Staff and regional combatant commanders.

Obama will leave the White House on January 20, when Donald Trump is sworn in as the 45th president of the United States.

Trump's mercurial personality and meteoric rise to become the world's most powerful man has led to a slew of questions about how he will wield that power.

Against that backdrop Obama made comments about the military's role that would be unremarkable at any other time, but today appear laden.

"My optimism about America going forward is in part because we have such an amazing military," Obama said.

The armed forces, he said, is "not only one that knows how to fight, but also knows how to uphold the values of the rule of law, professionalism, integrity and recognizes our constitutional structure and maintains strict adherence and respect for civilian authority and democratic practices in determining how we use the awesome force of the American military."

During the 2016 election campaign, the presence of several high profile retired generals at campaign events had prompted questions about the politicization of the military.

Almost 100 retired generals and other senior officers endorsed Hillary Clinton.

Retired general Mike Flynn campaigned for Trump -- and has been tapped to become his national security advisor.

Trump has also nominated retired general James Mattis to become Secretary of Defense and retired general Jon Kelly to run the Department of Homeland Security.

The election-time furor prompted Chairman of the Joint Chiefs of Staff Joseph Dunford -- who was at the White House meeting Wednesday -- to write an open letter in October about the military's role during elections.

"While we must always safeguard our professional integrity, extra vigilance is required during any political transition," he wrote.

"Our individual and collective obligation during this election season is twofold. First, we must recognize that we have one Commander in Chief, and until authority is transferred on January 20, 2017, the Joint Force must remain clearly focused on and responsive to the existing national command authority."

"Second, the Joint Force must conduct itself in such a way that the new administration has confidence that it will be served by a professional, competent, and apolitical military. "