PALM BEACH, FLORIDA - US President Donald Trump has tapped Army Lieutenant General Herbert McMaster, a prominent military strategist known as a creative thinker, as his new national security adviser, replacing the ousted Michael Flynn.

Trump announced the pick on Monday at his Palm Beach, Florida, club and said McMaster is "a man of tremendous talent and tremendous experience".

Sitting next to Trump for the announcement, McMaster said he was honored to take on the role and added that he looks forward to "doing everything that I can to advance and protect the interests of the American people".

The president's choice further elevates the influence of military officers in the new administration.

Trump, who has no military or foreign policy experience, has shown a strong preference for putting generals in top roles. In this case, he tapped an active-duty officer for a post that's sometimes used as a counterweight to the Pentagon. McMaster, who wore his uniform for the announcement, joins Defense Secretary Jim Mattis and Homeland Security Secretary John Kelly, both retired generals, in Trump's inner circle of national security advisers.

The White House said on Monday McMaster plans to remain on active military duty.

He will take on the challenge of leading a National Security Council that has not adjusted smoothly to Trump's leadership. The president suggested he does not trust holdovers from the Obama administration and complained about leaks to reporters.

McMaster is viewed as soldier-scholar and creative thinker. He has a doctoral degree in history from the University of North Carolina and has been heavily involved in the army's efforts to shape its future force and its way of preparing for war. He is the director of the Army Capabilities Integration Center, a sort of military think tank, at Fort Eustis, Virginia.

Second choice

Outside of the army, he may be best known for his 1997 book, Dereliction of Duty, a searing indictment of the US government's mishandling of the Vietnam War and an analysis of what he called the "lies that led to Vietnam". The book earned him a reputation for being willing to speak truth to power.

McMaster was Trump's second choice to replace Flynn, who has been under FBI investigation for his contacts with Russian officials.

Trump's first choice to replace Flynn, retired vice-admiral Robert Harward, turned down the offer.