The US market has long been considered one of the most mature on the planet; modest year-on-year growth, some chopping and changing of destinations and connectivity to major hubs, and a perception of limited international growth - but is that still true?

In recent years, the big three US legacy airlines have launched more new year-round and seasonal services than ever, responding to shifting geopolitics and factors like the strength of the US dollar. Here, we dive into the data to explore what is a dynamic story of change.

US Airlines’ International Growth: What the Data Shows

Comparing the number of countries served shows modest expansion since 2019 for Delta and United, while American Airlines now operates to fewer markets. A more short-term comparison of this year’s schedules against the summer 2025 programme shows United dropping three country markets, while Delta and American are adding new destinations.

• United’s loss of three country markets this summer compared with last year is not unexpected. Cuba remains politically complex for US carriers, while Sweden presents commercial challenges following SAS joining the SkyTeam alliance.
• Delta’s new destinations combine strategic moves and seasonal opportunities. Malta will operate as a summer-only route, two Caribbean destinations extend winter programmes, and Saudi Arabia reflects plans for a future partnership with Riyadh Air - assuming the airline launches services in 2026.
• American Airlines’ additions are largely leisure-driven. Services to the Czech Republic and Hungary are summer-focused, while the New Zealand launch consists of a single flight aligned with the start of the winter schedule.

Intriguingly, across the three carriers, there are very different development strategies that in part reflect recent long-haul aircraft deliveries and strategic partnerships with other carriers around the globe.

American Airlines: A Caribbean and Central America Focus

Since Summer 2019, American Airlines has concentrated its international growth in the Caribbean and Central America. The airline has added ten Caribbean destinations, including Bridgetown, Tortola, and Anguilla.

In Central America, Mexico and Costa Rica have seen frequency increases of 17% and 33% respectively. Dallas–Fort Worth has experienced the largest growth, with more than 1,500 additional flights since 2019. Meanwhile, Charlotte and Austin Bergstrom have both gained new services to Central America.

Growth in services to European destinations has been broadly consistent across all of the airline's hub airports. Philadelphia has seen the largest growth, with increases in frequency to Milan, Nice, Naples, and Copenhagen compared to Summer 2025.

Delta Air Lines: Leveraging the European Market

The European market has always been a key part of Delta’s international network, and since 2019 it has been the focus market for growth from the airline while all other regional markets have seen frequency drops. The carrier has added around nine daily flights to its European network, more than doubling frequencies to Italy as former commercial agreements with the Alitalia ceased, while reducing operations to Germany by 25% as the market continues to lag in its recovery. Intriguingly, this summer Delta will increase operations to Spain by 18% with a new Boston – Madrid service alongside existing services from Atlanta and New York.

United Airlines: Broad International Expansion

While its two major local competitors are perhaps more cautious in their international growth plans, United Airlines has pursued a broader international expansion strategy ,with Latin America and Europe seeing the largest gains. European frequencies have risen by 36%, with new summer routes to Glasgow and Bari highlighting the airline’s focus on seasonal leisure markets. Despite some route turnover, the only notable destination missing from United’s Summer 2019 network is Manchester, previously served daily from Newark.

United’s expansion also extends to Africa and the Southwest Pacific, markets it entered in Summer 2022 and continued to add frequency. Johannesburg now operates daily, Cape Town six times weekly, and both Lagos and Accra are year-round destinations. In Australia, United operates more than 850 summer flights from San Francisco and Los Angeles combined, serving Melbourne, Sydney, and Brisbane.

A key factor behind this growth has been United’s expanding Boeing 787 fleet, which now exceeds 80 aircraft. The aircraft’s efficiency has improved the economics of long-haul “long and thin” routes, giving United a cost advantage over both American and Delta. 

Looking Ahead

In the coming years, international networks will continue to evolve. Some destinations will be added, while others inevitably disappear as demand shifts. Leisure hotspots may fade, geopolitical factors may reshape markets, and partnerships will continue to influence route strategies.

With all three US majors holding substantial long-haul aircraft orders and new market opportunities emerging, further international expansion across their networks appears highly likely.