Defense Secretary Lloyd Austin has suspended the work of dozens of Pentagon advisory boards and asked hundreds of appointees to step down in what officials described as partly an effort to counteract a flurry of appointments that took place in the Trump administration’s final days.

Pentagon spokesman John Kirby said that the work of more than 40 boards would be halted over the next five months while Austin conducts a “zero-based review,” which also seeks to optimize the bodies’ work. Members of the boards who were appointed by the Pentagon will be asked to resign this month, while those who were selected by Congress or by the president, in this case President Donald Trump, will stay on while the review takes place, Kirby told reporters at the Pentagon.

The decision follows a move last week to halt the appointment of Trump loyalists on some of those boards, including one that had been given the task of evaluating how to rename military installations whose names now honor Confederate military figures. Those appointees included two men who worked as campaign managers for Trump, Corey Lewandowski and David Bossie.

“The secretary was deeply concerned with the pace and the extent of recent changes to memberships of department advisory committees,” Kirby said.

Officials, speaking to reporters on the condition of anonymity to preview the decision before Kirby’s news briefing, said the move would affect several hundred appointees, who typically serve in a volunteer capacity. They said Austin hoped to review the mission of each of the bodies, some of which overlap in scope.

Among the higher-profile bodies are the Defense Policy Board and the Defense Business Board. The work of military academy boards of visitors also will be suspended, but their members, who are presidentially appointed, will not be asked to resign, officials said.

The moves follow the Trump administration not only installing loyalists on some of the boards but also abruptly removing others, many of whom had served in a nonpartisan capacity across more than one presidential administration.

Joshua Whitehouse, a former Trump administration appointee who had a leading hand in removing the officials as a White House liaison at the Pentagon, said Tuesday that he was “not surprised in the least bit” by Austin’s decision.

“This administration wants to revise history to fit its political agenda,” Whitehouse said. “There is no unity, as Biden suggests.”

Whitehouse, whose own recent Trump-era appointment to a panel considering how to rename Army bases that recognize Confederate military officers was affected by Austin’s decision, accused Austin of coming “out of war profiteering” to take the job, an apparent reference to his former spot on the board of directors at Raytheon. Austin has resigned from that position. Many Trump administration officials had similar ties.

Whitehouse said Lewandowski has “good intentions” and alleged without providing evidence that those the Trump administration had removed from the Pentagon boards had served on them “for the purpose of boosting their paycheck.”