U.S. Transportation Secretary Sean Duffy says that he's planning to pull $160 million in federal highway funds from California, over claims that the state has been illegally issuing commercial truck driver's licenses to noncitizens.

In an October 26 interview on Fox News, Duffy alleged that California has unlawfully issued at least 60,000 commercial driver's licenses to noncitizens operating fuel tankers, semi-trucks and school buses among other heavy-duty vehicles. The U.S. Department of Transportation began auditing CDLs across the U.S. after a foreign-born truck driver in Florida reportedly made an illegal U-turn that caused a crash that killed three people in Florida.

Speaking to the Associated Press, California Department of Motor Vehicles spokesperson Eva Spiegel denied that the state is in violation of any federal laws, and asserted that there is "no legitimate basis" for withholding California's highway funds. Spiegel added that the federal government has allowed states to issue CDLs for asylum seekers and refugees, and only recently halted the policy on September 29 in response to the fatal semi-truck crash in Florida.

Read More: 3K Truckers Taken Off U.S. Roads in Language Proficiency Crackdown

This comes after Duffy previously threatened to withhold another $40 million in federal funds from California over failing to properly enforce new English proficiency language requirements. Starting on June 25, the Trump administration directed states to take truckers off the job if they can't demonstrate sufficient English proficiency during routine traffic stops and safety inspections. In an audit of California's enforcement efforts, USDOT found violations of the new language standards in 34,000 inspections in August, despite the state removing just one truck driver from service over that period.