Rob Joyce, a former high-ranking U.S. cybersecurity official, warned lawmakers on Wednesday that reducing the number of federal probationary employees would have a severely detrimental effect on the nation’s security.

Joyce, who served as the director of cybersecurity at the National Security Agency until his retirement in 2024, was testifying before the U.S. House Committee on the Chinese Communist Party, which is currently investigating a widespread hacking campaign by China that has targeted the U.S. government in recent years.

“I would like to express my serious concerns that the proposed cuts to U.S. government probationary employees will have a profoundly negative impact on our national security and cybersecurity,” Joyce stated.

Probationary staff refers to federal employees who have been working for the government for less than a year. The Trump administration has attempted to terminate nearly all probationary workers since taking office. However, a federal court has temporarily halted the mass firings.

According to Joyce, eliminating probationary federal employees would “destroy a pipeline of top talent responsible for identifying and eliminating threats backed by China.”