The Trump administration has fired the chief government watchdog at the U.S. Agency for International Development after it warned it no longer had the resources to oversee the gutted agency, officials said Tuesday.

Multiple U.S. officials, speaking on condition of anonymity, said the White House didn't give a reason for its firing of Inspector General Paul Martin. Martin's office had warned the administration that shuttering USAID meant there would no longer be oversight of some $8.2 billion in unspent aid funds.

USAID's inspector general, like most agency watchdogs, are independently funded and charged with countering abuse and fraud at their assigned agencies. At USAID, the role involved making sure that aid funds and resources didn't get allocated to violent extremists or mishandled in conflict zones.

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Trump has fired watchdogs at at least 17 other government agencies since taking office, including the Departments of Agriculture, Commerce, Defense, Education, Energy, Health and Human Services, Housing and Urban Development, Interior, Labor, State, Transportation, Treasury and Veterans Affairs.

The dismissals drew questions and warnings from Congress.

Senator Chuck Grassley, chairman of the Judiciary Committee, and Sen. Dick Durbin, its ranking member, sent a letter to Trump last week.

“While IGs aren’t immune from committing acts requiring their removal, and they can be removed by the president, the law must be followed,” the letter warns.

The Inspector General Reform Act of 2008 requires the president to “communicate in writing the substantive rationale, including detailed and case-specific reasons for any such removal or transfer to both Houses of Congress not later than 30 days before the removal or transfer.”

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White House officials have called that 30-day buffer unconstitutional and defended President Trump's decisions.

“It is the belief of this White House and White House Counsel's Office that the President was within his executive authority to do that. He is the executive of the executive branch, and therefore he has the power to fire anyone within the executive branch that he wishes to,” White House press secretary Karoline Leavitt told reporters during her first press briefing Tuesday, pointing to prior case law.