U.S. Defense Secretary Pete Hegseth on Friday issued orders that require journalists to have official escorts within much of the Pentagon building, the latest in a series of Trump administration restrictions placed on the press.

The measures, which take effect immediately, bar credentialed reporters from most of the Department of Defense headquarters in Arlington, Virginia, unless they have official approval and an escort.

"While the Department remains committed to transparency, the Department is equally obligated to protect CSNI (classified intelligence) and sensitive information - the unauthorized disclosure of which could put the lives of U.S. Service members in danger," Hegseth said in a memorandum.

He called the protection of classified national intelligence information and operational security "an unwavering imperative for the Department."

The Pentagon Press Association, a membership organization representing the interests of the press corps covering the U.S. military, said the new rules appeared to be a "direct attack on the freedom of the press."

"The decision is purportedly based on concerns about operational security. But the Pentagon Press Corps has had access to non-secured, unclassified spaces in the Pentagon for decades, under Republican and Democratic administrations, including in the aftermath of the Sept. 11, 2001, attacks, without any concern about OP-SEC from DoD leadership," the statement said.

The Pentagon did not immediately respond to a Reuters request for comment on the press association's statement.