YUMA, Ariz. (AP) — Arizona Gov. Doug Ducey demanded that President Joe Biden’s administration do more to secure the U.S.-Mexico border as local officials in Yuma report an increase in asylum-seekers crossing into southwestern Arizona.

As Ducey and local officials spoke at a lectern on the border near Yuma, nearly a dozen people crossed between a gap in the border fence behind them, according to video posted on Twitter by a KPNX-TV reporter. A livestream of the news conference showed several people wearing blue surgical masks walk up and watch from a short distance behind the governor, the Yuma mayor, the local sheriff and others as security personnel kept watch.

“We need the force of the federal government to secure the border,” Ducey told reporters. “That’s their job. We’re asking the Biden administration to do it.”

Ducey on Tuesday faulted the Biden administration for incrementally reinstating former President Donald Trump’s policy requiring asylum-seekers to stay in Mexico as they await immigration hearings. The administration last week reluctantly announced plans to reinstate the Trump-era policy and agreed to Mexico’s conditions for resuming it.

The reinstated policy began Monday in El Paso, Texas. Ducey said the piecemeal implementation led migrants to rush to other parts of the border and cross into the U.S. before the policy is rolled out more widely.

More than 1,500 migrants crossed the border illegally Monday, overwhelming Border Patrol agents in the Yuma Sector, the Yuma Sun reported. Several large groups clustered on the U.S. side and waited to be apprehended to make asylum claims. A majority of migrants have come from Cuba, Brazil and Venezuela, the newspaper reported.

Ducey said the Arizona National Guard will send a helicopter, six vehicles, four all-terrain vehicles and 24 people to help law enforcement.

The Republican governor has been a frequent critic of Biden’s border policies. The GOP sees rising border crossings as a top issue to target Biden and other Democrats in the 2022 election.

“As things stand right now, this crisis will not be resolved as long as Joe Biden is our president,” Ducey said.

Revival of the “Remain in Mexico” policy comes even as the Biden administration maneuvers to end it in a way that survives legal scrutiny. Biden scrapped the policy on his first day in office, but a lawsuit by Texas and Missouri forced him to put it back into effect, subject to Mexico’s acceptance.

Illegal border crossings fell sharply after Mexico, facing Trump’s threat of higher tariffs, acquiesced in 2019 to the policy’s rapid expansion. Asylum-seekers were victims of major violence while waiting in Mexico and faced a slew of legal obstacles, such as access to attorneys and case information.

White House press secretary Jen Psaki last week described the policy as “deeply flawed” but said the administration was working to implement it under the court order.