The Trump administration escalated its attack on Columbia University on Wednesday by taking a warning shot against its accreditation, a key credential that U.S. universities need to receive federal student aid.

The federal Education Department’s Office for Civil Rights, which two weeks ago found that Columbia violated civil rights laws by “acting with deliberate indifference” toward the harassment of Jewish students, sent a letter on Wednesday to the Middle States Commission on Higher Education, the nongovernmental organization that accredits Columbia.

The letter said that because Columbia was in violation of federal anti-discrimination laws, the Education Department believes it fails to meet the standards for accreditation.

“University accreditors have an obligation to ensure member institutions abide by their standards,” Linda McMahon, the federal education secretary, said in a news release. She said the government looked forward to being “fully informed of actions taken to ensure Columbia’s compliance with accreditation standards, including compliance with federal civil rights laws.”

President Trump has described the accreditation process as his “secret weapon” to force ideological changes at universities. But the Trump administration does not have direct control over which universities are accredited. Instead, those decisions are made by nongovernmental organizations certified by the government, in a complex process meant to insulate universities from political interference.

Experts on the process said that despite the letter, Columbia faced no immediate threat that its accreditation would be revoked, a process that typically takes years.