Virginia Republican Gov. Glenn Youngkin warned of an impending national emergency if Title 42 is lifted.
The U.S. Supreme Court on Monday said Title 42 should remain in place temporarily as a Republican legal challenge moves forward. The Trump administration implemented the health-related policy in March 2020 to help limit immigration during the COVID pandemic.
Before Chief Justice John Roberts' latest ruling, a federal judge last month had given the Biden administration until Wednesday to end the policy.
"It's beyond belief that we're having to appeal to our Supreme Court to do something that the Biden administration should have already done or we should get Congress to do," Youngkin said Monday on Fox News.
"If Title 42 goes away, they're expecting there to be 5 million people a year to come across the border in 20 months. That's an entire state of Virginia coming across the border. It's unbelievable."
The Supreme Court gave both sides in the legal dispute until Tuesday at 5 p.m. ET to respond. The order means Title 42 will stay in place as the legal arguments play out.
Youngkin cited the impact of the migrant surge on the U.S. drug crisis, which has been fueled by Mexican cartels.
"We had a record number of overdoses in Virginia, and 76% of them come from fentanyl. And we know where the fentanyl comes from. It's time to act," Youngkin said during the Fox interview.
"Every state is a border state, and that's why you'll see governors, Republican governors, standing up together in order to try to pressure Washington to cleave secure border."
The Washington Post last week reported that fentanyl, a potent synthetic opioid, is the leading cause of death for Americans ages 18 to 49, and an estimated 196 Americans are dying each day from the drug.
The Post said federal officials estimate they are capturing only 5% to 10% of the fentanyl crossing from Mexico.
Youngkin also was asked whether he planned to run for the 2024 Republican presidential nomination.
"I'm always so humbled on this topic — 2024 is a long way away," he said. "We'll see what happens between here and there."
Reuters contributed to this story.