The introduction of four new nonstop international flights from Denver International Airport, including a first direct flight to Rome, has accelerated DIA’s development as a global hub as international air traffic grows more than twice as fast as domestic traffic.

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

Travelers can now fly non-stop to 33 destinations in 18 countries with DIA. 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 are forecasting a record 4.6 million international travelers this year, up from 3.9 million in 2023, up about 20% from 2022, said Airport officials.

International air traffic rose 16.4% between October 2023 and October 2024, compared to a 6.7% increase in domestic air traffic, the latest airport data shows.

The new flights represent “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 well-paid workforce have favored international flights. DIA analysts also cited the diversity of Colorado’s population, including residents with relatives abroad, as a factor, Jackson said.

According to surveys, 29% of DIA’s international travel is business, 34% is leisure and 37% is leisure.

“This is a healthy, resilient mix that will help protect Denver from declines in travel demand,” Jackson said. “Another important factor driving these increases is that Denver, Colorado, is an attractive and unique inbound destination for both tourism and business conventions.”

The simultaneous growth in nonstop domestic 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 lift.”

United’s new nonstop service between Denver and Rome will be seasonal, operating from May 1 to September 24. The flight to Regina begins May 15th.

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

Last year, DIA lured Viva Airlines with nonstop flights to Monterrey, Mexico, then a new destination. Ireland’s airline Aer Lingus started non-stop flights to Dublin on May 17th. 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, Fla.; Peoria, Ill.; North Bend, Ore.; Redding, California; and Wilmington, North Carolina.

DIA’s number of flights to domestic destinations is expected to reach 187 in 2025, according to airport data.

United added nonstop flights to Harlingen, Texas, last year; Fairbanks, Alaska; and West Palm Beach, Florida. In 2025, United is scheduled to offer a new nonstop service to Butte, Montana, starting January 3, and Allegiant Airlines plans a new nonstop service to Stockton, California, starting May 22.