The unveiling of four new nonstop international flights from Denver International Airport, including a first direct flight to Rome, has boosted DIA’s emergence as a global hub with international air traffic surging more than twice as fast as domestic travel.

Aeromexico on Saturday will announce nonstop flights from DIA to Monterrey and Guadalajara, airport officials said, and United Airlines officials on Thursday unveiled the 5,563-mile flight to Rome, starting May 1, along with a flight to Regina, Canada.

Travelers at DIA now can fly nonstop to 33 destinations in 18 countries. These destinations include nine in Europe, eight in Mexico, seven in Canada, five in Central America, three in the Caribbean and one in Asia.

The new flights unveiled this week are expected to accelerate growth at DIA, where officials project a record 4.6 million international travelers this year, up from 3.9 million in 2023, which was up about 20% from 2022, airport officials said.

International air traffic increased by 16.4% between October 2023 and October 2024, compared with a 6.7% increase in domestic air travel, the latest airport data shows.

The new flights demonstrate “extraordinary progress” toward Denver leaders’ goal of expanding global connections, said Laura Jackson, the airport’s vice president for air service development.

Population growth along Colorado’s Front Range and a relatively high-wage workforce has favored international flights. DIA analysts also cite the diversity of Colorado’s population, including residents with relatives abroad, as a factor, Jackson said.

Surveys break down DIA’s international travel as 29% for business, 34% for leisure, and 37% for personal reasons.

“That is a healthy, resilient mix that helps to insulate Denver from downturns in any one type of travel demand,” Jackson said. “Another important factor that has driven these increases is that Denver, Colorado, is an attractive and unique inbound destination, both for tourism and for business conventions.”

Simultaneous growth in domestic nonstop flights, as DIA becomes United Airlines’ busiest hub, further increases the flow of travelers for long-haul transatlantic and transpacific flights, she said. “It’s the power of the hub.”

United’s new nonstop flight linking Denver to Rome will be seasonal, running May 1 through Sept. 24. The flight to Regina starts May 15.

“This expansion strengthens Denver’s position as a global hub and provides our community with even greater connectivity to the world,” DIA chief executive Phil Washington said.

Over the past year, DIA attracted Viva Airlines with nonstop flights to Monterrey, Mexico, which was, at the time, a new destination. Ireland’s Aer Lingus on May 17 launched nonstop flights to Dublin. On June 11, Turkish Airlines announced a 13-hour, 6,130-mile flight from Denver to Istanbul, the longest nonstop route from DIA.

This week, United officials also unveiled new nonstop flights to six U.S. cities: Buffalo, New York; Pensacola, Florida; Peoria, Illinois; North Bend, Oregon; Redding, California; and Wilmington, North Carolina.

Flights from DIA to domestic destinations in 2025 are expected to number 187, according to airport data.

United added nonstop flights this past year to Harlingen, Texas; Fairbanks, Alaska; and West Palm Beach, Florida. In 2025, United is scheduled to add a new nonstop flight to Butte, Montana, starting Jan. 3, and Allegiant Airlines plans a nonstop to Stockton, California, starting May 22.