(NewsNation) — The city of Denver has issued an emergency declaration after hundreds of undocumented migrants came to the mile-high city unexpectedly.

The recent migrant influx is putting a strain on the city’s resources to the tune of of more than $800,000. Migrants have been trickling into the city over the past several months, and most recently a bus carrying 90 immigrants arrived.

Denver mayor Michael Hancock said Friday on “Rush Hour” that the city is need of volunteers, staff and space to handle the number of people that are seeking assistance at homeless shelters.

“We are in dire need of volunteers to help staff the facilities,” Hancock said. “Had it not been for some of the NGOs, nonprofit profits and faith-based organizations, our city would have been certainly at the brink if not broken in terms of trying to provide services.”

Some 800 migrants have arrived in Denver since Dec. 9, Hancock said, forcing the city to convert two of its largest recreational centers into shelters. City staff are being reassigned to work at the shelters, diverting them from their regular duties.

“Once we activate our emergency operations center, they leave their title roles and they go fill roles either in the operation center or they could be reassigned as other duties are needed,” Hancock said. “They’re not going back to their desk, but many of them are working exorbitant hours because we are short-staffed in our shelter centers.”

The migrants’ arrival in Denver comes as others have been bused north from Texas and Arizona to cities including Chicago, Philadelphia and New York City. The governors of those states have said northern states should share in the responsibility of assisting the migrants who are arriving at the southern border in record numbers.

Hancock said there’s no indication that Denver is the latest city to be included in that effort.

“It seems to be loosely coordinated between the migrants and asylum-seekers themselves and some nonprofit partners on the ground in El Paso, Texas,” Hancock said. “They’re coming in at our homeless shelters, and as a result because of the surge we had to set up these separate shelters.”

More than 2.37 million migrant encounters were logged at the southern border in fiscal year that ran from Oct. 1, 2021 to Sept. 30, 2022, a 37% jump from the previous year. Several Biden administration officials, including Homeland Security Secretary Alejandro Mayorkas, have described the southern border as being “secure” despite the increase in arrivals.

Local officials and law enforcement on the ground have repeatedly expressed their frustration over the issue, and Hancock did, too. He said the the city of Denver is more than happy to assist migrants, but he urged the federal government to put the right tools and resources in places to help achieve that goal.

“When we have 110, 170 people showing up in one night and it continues to be a constant cadence, it overwhelms our system. I can’t imagine what the mayor of El Paso, Texas, is having to deal with, 5,000 coming in,” Hancock said. “Congress literally needs to put aside their partisan politics and come to the rescue of these individuals, but also help these cities and states server their purpose in helping these individuals.”