Frontier Airlines will double its operations at Minneapolis-St. Paul International Airport this spring, adding nonstop service to five domestic destinations.

Starting in April, the budget carrier will fly to Dallas and Atlanta four times a week. Then in May, Frontier will begin daily service to Philadelphia, four-times-a-week service to Cleveland and three weekly flights to Cincinnati. All routes are new, except for Cleveland and Cincinnati, which are resumptions from 2019.

As the cost of airfares dips, the expansion of Frontier's small operation at MSP brings a bit more rivalry to an airport Atlanta-based Delta Air Lines dominates. Minneapolis-based Sun Country Airlines, which targets the same leisure travelers as Frontier, is MSP's second-largest carrier.

"It will hopefully stir up competition, which our cities greatly need," A1 Travel Consultant Monique Delph said. "We all love Delta, but they own our city and drive up prices because they can."

Although Delph welcomes the opposition, the travel agent doesn't frequently book Frontier Airlines for her customers.

"By the time you add in all the extras, it's not always necessarily a savings," she said.

Henry Harteveldt, a travel industry analyst who's president of Atmosphere Research Group, expects Frontier's expansion to provoke Delta — which caters to premium travelers — into offering more basic economy fares on competing routes.

But he offers this warning: "Budget airlines like Frontier do not hesitate to cancel routes they've announced if advance bookings don't meet the airline's forecast."

These services bring Frontier's nonstop MSP routes to 10. Frontier already offers existing nonstop service from MSP to Denver, Phoenix, Orlando, Fort Myers and Cancún.

"From across the Midwest and to the South, this announcement represents meaningful expansion for Frontier at MSP as part of our new focus on underserved and overpriced routes," said Josh Flyr, Frontier's vice president of network and operations design, in a statement.

Brian Ryks — chief executive of the Metropolitan Airports Commission, which owns and operates MSP Airport — said in a statement the commission is "excited to see the growth in service with Frontier's announcement to serve five additional markets in their network from MSP, including new routes to Atlanta, Dallas and Philadelphia."

Increased international competition also is on the way to MSP. German carrier Lufthansa will begin nonstops from MSP to Frankfurt, and the Irish flag carrier Aer Lingus is resuming pre-pandemic service to Dublin.

Condor, a German carrier flying seasonally to Frankfurt, will provide even more competition on the German route.

Correction: A previous version of this story incorrectly characterized Frontier's routes from MSP to Cleveland and Cincinnati. Those routes are resuming.