Voice of America, the federally funded broadcaster to the world, has long prided itself on serving as an accurate and fair source of news and on being independent of whichever president and party are in power in the United States.

Since the election of President Trump, that independence is increasingly being tested.

In recent months, Voice of America’s parent organization, the U.S. Agency for Global Media, has opened human-resources investigations into Voice of America journalists for reporting on criticism of Mr. Trump or for making comments that were perceived as critical of him, according to several employees. Some journalists raised concerns about the investigations in a meeting this week with the broadcaster’s director.

At least a couple of articles that included criticism of Mr. Trump and his administration were not published or were watered down after publication in recent months, said three Voice of America employees, who spoke on the condition of anonymity because they feared retribution.

And on Friday, the Agency for Global Media informed one of Voice of America’s highest-profile journalists, Steven Herman, that he was being placed on an extended “excused absence” pending a human resources investigation, according to a copy of the letter reviewed by The New York Times. Mr. Herman confirmed receiving the letter, which said the investigation was into whether his “social media activity has undermined V.O.A.’s audiences’ perceptions of the objectivity and/or credibility of V.O.A. and its news operations.”

Weeks earlier, Mr. Herman came under fire from the Trump administration when he cited a quote on social media from an anticorruption watchdog group criticizing cutbacks at the United States Agency for International Development.

Richard Grenell, Mr. Trump’s envoy for “special missions,” wrote on X that Mr. Herman’s comments were “treasonous.”

“You don’t get to work against the official U.S. government policies while being paid by US taxpayers,” Mr. Grenell continued. “You should be immediately fired.”

Also on Friday, Voice of America officials informed Patsy Widakuswara, the broadcaster’s longtime White House bureau chief, that she was being involuntarily reassigned to another beat, employees said. Some Voice of America journalists suspected the move was part of an effort to reduce friction with the Trump administration, although an official at the broadcaster, who wasn’t authorized to talk to the media, denied that.

The Agency for Global Media declined to comment.

The upheaval at Voice of America comes amid a series of broadsides against the media by the Trump administration. The White House has started selecting which news outlets are part of the press pool that covers the president, and it has barred The Associated Press from events because it won’t reclassify the Gulf of Mexico as the Gulf of America. The Federal Communications Commission has opened investigations into whether broadcasters are acting in the public interest. And Mr. Trump has filed or threatened lawsuits against news outlets whose coverage he objected to.

Journalists at Voice of America have been fretting about their future ever since Mr. Trump said he would appoint Kari Lake, a former television news anchor and failed Republican Senate candidate who has frequently spread lies and conspiracy theories, to lead the broadcaster.

Ms. Lake has rebuffed calls from Elon Musk and Mr. Grenell to abolish Voice of America altogether. But she has said the broadcaster’s coverage will be free from what she described as “Trump derangement syndrome,” or T.D.S.

“It won’t become Trump TV,” Ms. Lake said during a speech this month at the Conservative Political Action Conference, an influential gathering of conservatives. “But it sure as hell will not be T.D.S.”

Under federal law, the Voice of America’s director must be approved by a bipartisan board that oversees the Agency for Global Media. The board has not voted on Ms. Lake’s nomination.

The Agency for Global Media told employees in an email on Thursday that, pending her formal approval by the board, Ms. Lake had been named a senior adviser to the media agency and to Voice of America.

“In this capacity she will oversee and advise agency leadership on administration priorities,” the email said.

Mr. Trump has nominated Brent Bozell, a conservative activist and media critic, to run the Agency for Global Media. Mr. Bozell needs to be confirmed by the Senate.

Even before Ms. Lake’s and Mr. Bozell’s arrivals, officials at Voice of America and its parent agency were tamping down on anti-Trump sentiment.

Shortly after the presidential election in November, Mr. Herman, who is the broadcaster’s chief national correspondent, was interviewed on a Voice of America program and was asked about the criteria that Mr. Trump was using to select cabinet nominees.

“What we’re seeing, again, loyalty being the No. 1 attribute rather than experience,” Mr. Herman responded.

Mr. Herman was soon summoned to a meeting with human resources officials at the Agency for Global Media, according to people familiar with what transpired. He was pressured to acknowledge that he had improperly engaged in speculation and analysis. Two other Voice of America journalists said they had encountered similar blowback.

The official at Voice of America, who wasn’t authorized to talk to the media, defended the investigations as part of an effort to safeguard the perceived objectivity and neutrality of Voice of America’s journalism when it is under intense scrutiny by Republicans in the White House and on Capitol Hill.

David Z. Seide, a lawyer at the Government Accountability Project who defends federal whistle-blowers, represents Mr. Herman and other Voice of America employees who face human resources investigations for what they wrote or said about Mr. Trump and his administration. He said it was notable that those investigations were taking place before Ms. Lake or other senior Trump appointees took the helm.

“They’re acting pre-emptively,” Mr. Seide said. “They can read the handwriting on the wall.” He added that he saw the social media investigation into Mr. Herman as a pretext for ousting one of Voice of America’s most prominent journalists.

Longtime Voice of America journalists said they were surprised and alarmed that the Agency for Global Media was scrutinizing their editorial decisions. To preserve Voice of America’s independence, the agency is supposed to be walled off from questions about its journalism.

At a meeting this week in Voice of America’s newsroom in Washington, the broadcaster’s director, Michael Abramowitz, faced questions from employees who worried that the human resources investigations would have a chilling effect on Voice of America journalists, leading them to mute any criticisms of the Trump administration, people who attended the meeting said.

Mr. Abramowitz, a longtime and well-regarded reporter and editor at The Washington Post who took the Voice of America job less than a year ago, responded by noting that he was acting as “a caretaker” and that Ms. Lake would soon replace him, the attendees said.

In his first term, Mr. Trump’s White House publicly criticized Voice of America’s editorial decisions. In 2020, Mr. Trump appointed Michael Pack, an ally of his former aide Stephen K. Bannon, to run the Agency for Global Media.

Mr. Pack was accused of trying to turn Voice of America into a mouthpiece for the Trump administration, and a federal judge ruled that Mr. Pack had violated the First Amendment rights of the outlet’s journalists. A federal investigation later found that he had mismanaged the Agency for Global Media, repeatedly abusing his power by sidelining executives he felt did not sufficiently support Mr. Trump.