ALSO SEE: Chaos on California’s I-5 as Marines’ Live-Fire Drill Stirs Backlash

The announcement came after Gov. Gavin Newsom (D) traded jabs with the White House over the live-fire exercise Vice President JD Vance is attending in the area.

A major stretch of highway between Los Angeles and San Diego was temporarily closed Saturday because of a live-fire exercise the U.S. Marine Corps is holding for its 250th anniversary, an event that has sparked a row between California Gov. Gavin Newsom (D) and the Trump administration.

“The President is putting his ego over responsibility with this disregard for public safety,” Newsom said in a statement. “Firing live rounds over a busy highway isn’t just wrong — it’s dangerous.”

The sudden announcement Saturday came after Newsom’s office traded jabs with the White House this week over the necessity of firing live munitions in the area and whether the highway needed to close as a result. On Saturday afternoon, the White House said on social media that Newsom “is lying.”

“He closed the highway — not only did nobody at the White House or the Marines ask him to do so, the Marines repeatedly said there are no public safety concerns with today’s exercises,” the administration’s rapid response account said in a post on X.

Newsom, a potential 2028 Democratic presidential candidate, had called the exercise a “vanity parade” for President Donald Trump and Vice President JD Vance, who will be in attendance with a production crew to film the event for a national broadcast next month. Representatives for Vance referred to the Marine Corps’ statement when asked for comment.

In response to questions Saturday, Marine spokesman Capt. Gregory Dreibelbis said the service did not request that the highway close. He added that the live-fire exercise will involve M777 howitzer artillery firing over a portion of Interstate 5 with “all safety precautions in place.”

As of Friday, the highway was supposed to remain open. Hours after Newsom complained Wednesday that the event would shut down a portion of I-5, the Marine Corps issued a statement saying “no public highways or transportation routes will be closed” and that “all training events will occur on approved training ranges and comport with established safety protocols.”

But on Saturday morning, Newsom’s office said that a section of I-5 will indeed close at the recommendation of traffic safety experts at the California Highway Patrol.

The decision was made after the federal government canceled train services that run parallel to I-5 on Saturday, between Orange and San Diego counties, Newsom’s office added. Late Friday, state authorities also received notice from event organizers asking for California Department of Transportation signage to be posted along the I-5 freeway that would read “Overhead fire in progress.”

“Early Saturday morning, after the state inquired once again for details, the federal government informed the state that live fire activities have now been scheduled for 1:30 p.m. today,” Newsom’s office said Saturday. “Due to extreme life safety risk and distraction to drivers, including sudden unexpected and loud explosions, a section of I-5 will be closed for a period on Saturday.”

Newsom’s office called I-5 “Southern California’s economic backbone,” serving as a major route for tens of thousands of travelers and moving $94 million in freight every day between San Diego and Orange counties.

“Thousands of truck shipments count on uninterrupted access,” Newsom’s office said. “Because of the federal government’s plans, drivers should expect delays on Interstate 5 and other state routes throughout Southern California before, during and after the event.”

Newsom also has criticized the event at Marine Corps Base Camp Pendleton as a show of force, scheduled the same day that anti-Trump demonstrators will march in several No Kings protests around the country, including in California. The first wave of No Kings protests in June coincided with Trump’s military parade in Washington.

“Using our military to intimidate people you disagree with isn’t strength — it’s reckless, it’s disrespectful and it’s beneath the office he holds,” Newsom said Saturday. “Law and order? This is chaos and confusion.”