US carrier United Airlines is continuing to push its strategy of expanding and restructuring its domestic route network as it seeks to close the gap on Delta and American.

Since the end of March, the Chicago-based airline has announced plans to open 33 new domestic routes from its seven hubs.

The latest is a daily service between Washington Dulles International Airport and Miami International Airport, launching on 19 December 2018 with Airbus A319 aircraft.

Although only seasonal until 30 March 2019, United will offer a twice daily service during peak holiday travel from 24 December to 6 January.

In addition, the carrier is increasing frequencies between Washington Dulles and Orlando and Tampa. From 28 November to 6 January it will operate five daily flights to Orlando, and from 26 December to 26 January four daily flights to Tampa.

"We want to make United the first choice for customers when planning travel," said Ankit Gupta, United's vice president of domestic network planning.

"To do this we are focusing on the strengths of our hub cities, which are the largest centres for business and tourism travel in the country and key gateways for customers to easily and conveniently connect to thousands of cities throughout the United States and beyond.”

United's new domestic routes (April - July 2018):

United’s management team announced plans to grow domestic capacity in late 2016, with president Scott Kirby saying the airline had fallen behind its rivals and needed to expand its network to enable more connecting opportunities for customers.

Speaking to analysts following the publication of United’s second quarter financial results in July, Kirby said the airline has “just started unlocking” its full potential.

“We’ve seen some of our best results in our mid-continent hubs as we’ve increased overall connectivity and productivity,” he added. “We’re optimistic that the second half will continue that momentum.”