(NewsNation) — After more than 40,000 asylum-seekers have found their way to Denver and racked up more than $10 million in unpaid medical costs over the past years, city officials are struggling to keep up with costs linked to migrants seeking shelter and work.

The city has already allocated more than $100 million to provide shelter, medical care and schooling for asylum-seekers, Denver Mayor Mike Johnston says. However, that number could jump to as much as $180 million, 15% of Denver’s annual budget, as costs continue to rise.

Although the Mile High City has not seen the volume of migrants that other sanctuary cities like Chicago and New York have, Denver is in dire need of part of the $1.4 billion in federal funding President Joe Biden has devoted to assisting state and local governments in dealing with the migrant crisis, local officials said.

Jon Ewing, spokesperson for Denver Human Services, told “NewsNation Now” on Friday that in addition to federal financial assistance, the city is asking the government to expand work authorizations for migrants, many of whom arrive in the city unable to find employment legally.

“We always try to educate people and explain to them that we have limited resources — very limited resources — and we’re going to try and help you,” Ewing said. “(But) we also have to tell them, listen, this city is very expensive; it’s very unaffordable to live if you haven’t lived here before.”

About 4,000 people, mostly families, are currently living in city-run shelters, Ewing said.

Other cities, such as Chicago, have placed limits on how long migrants can remain in temporary shelters. Chicago Mayor Brandon Johnson has already extended deadlines twice after being criticized for establishing deadlines for when migrants must live.

Denver has previously extended its mandatory stay from 37 to 42 days, Ewing said. There are currently no plans to allow for longer stays because of the lack of resources available to city officials.

With more than 3,000 migrant students enrolled in Denver schools, covering education costs, along with those associated with housing and medical care, are only making things increasingly difficult for the city, Ewing said.

City officials are attempting to provide migrants with options, but because so many are not authorized to work in the United States, the city of 710,000 full-time residents is having to bear even more of the financial burden linked to asylum-seekers, he said.

What to do with migrants moving forward is the “million-dollar question,” Ewing told NewsNation.

“One of the main obstacles we run into is not an issue of who has the resources because no one has the resources,” Ewing said. “The issue we run into is they can’t support themselves because they’re not authorized to work — or at least a large number of them are not authorized to work. So we’ve continued to call on the federal government to expand that work authorization so they can get a job, they can work, and they can provide for themselves.”