Dozens of staffers were fired from the White House National Security Council on Friday, as President Donald Trump moved to slash the size and scope of the once-powerful body, five sources briefed on the matter said, Reuters reported.

Staff dealing with most major geopolitical issues, from Ukraine to Kashmir, were terminated in the afternoon, said the sources, who requested anonymity as they were not permitted to speak to the media.

The move came just weeks after Secretary of State Marco Rubio took over from Mike Waltz as national security adviser.

The NSC restructuring is expected to further reduce the agency's influence, transforming it from a powerful policymaking body into a small organization focused more on implementing the president's agenda than on shaping it, the sources said, according to Reuters.

In practice, the move is expected to grant more authority to the State Department, the Defense Department and other departments and agencies involved in diplomacy, national security and intelligence matters, the sources said.