In an appearance on Fox News Channel’s “Sunday Morning Futures,” Duffy said Gov. Gavin Newsom has refused to comply with Department of Transportation rules that require the state to stop issuing such licenses and review those already issued.

“So, one, I’m about to pull $160 million from California,” Duffy said. “And, as we pull more money, we also have the option of pulling California’s ability to issue commercial driver’s licenses.”

A Newsom spokesperson referred a request for comment to the state’s transportation agency, which did not immediately respond Sunday.

California has defended its practices previously. When Duffy threatened to revoke funds last month, a spokesperson for Newsom dismissed the attack and noted that CDL holders from California have a significantly lower rate of crashes than both the national average and that of Texas, which is the only state with more licensed commercial drivers.

Last month the Transportation Department tightened commercial driver’s license requirements for noncitizensafter three fatal crashes that officials said were caused by immigrant truck drivers. Only three specific classes of visa holders will be eligible for CDLs under the new rules and states must verify an applicant’s immigration status in a federal database. The licenses will be valid for up to one year unless the applicant’s visa expires sooner.

Duffy said last month that California should never have issued 25% of 145 licenses investigators reviewed. He cited four California licenses that remained valid after the driver’s work permit expired — sometimes years after. The state had 30 days to come up with a plan to comply or lose funding.

A nationwide commercial driver’s license audit began after officials say a driver in the country illegally made a U-turn and caused a crash in Florida that killed three people. It found licenses that were issued improperly in California, Colorado, Pennsylvania, South Dakota, Texas and Washington.

Duffy said Sunday that California has unlawfully issued tens of thousands of these licenses to noncitizens.

“So you have 60,000 people on the roads who shouldn’t have licenses,” Duffy said. “They’re driving fuel tankers, they’re driving school buses, and we have seen some of the crashes on American roadways that come from these people who shouldn’t have these licenses.”

Duffy said earlier this month that he would withhold $40 million from California because it is the only state that is failing to enforce English language requirements for truckers. California defended its practices in a formal response to the Transportation Department, but federal officials were not satisfied.

The investigation launched after the Florida crash found what Duffy called significant failures in the way California is enforcing rules that took effect in June after one of President Donald Trump’s executive orders. California had issued the driver a commercial license, but these English rules predate the crash.