Delta Air Lines says it is making big plans for its hub operations at the soon-to-be rebuilt Salt Lake City International Airport, including adding nonstop flights to Asia when it is finished.

“Salt Lake has been our fastest growing hub” in the United States, growing faster than Atlanta, Detroit and Minneapolis, Joe Esposito, Delta’s senior vice president of network planning, told the city’s Airport Advisory Board on Wednesday. He expects such growth to continue.

Since 2014, the number of seats Delta offers on flights here has increased more than 30%. It also operates nearly 3 of every 4 departing flights from Salt Lake City International.

That is a main reason the airport saw a record 25 million passengers pass through last year. It was designed to handle only 10 million. So the city is reconstructing the airport at a cost of $3.6 billion — with the first phase scheduled to open late next year. It is funded by passenger fees paid by Delta and other airlines.

The rebuilt airport will offer expanded gates for international flights, which Esposito said Delta is planning to utilize with extra offerings.

He said nonstop service from Salt Lake City to Seoul, South Korea, is “on our drawing board.”

Delta CEO Ed Bastian had let those plans slip in a speech here earlier this year, but later said he was simply discussing possibilities and not making any announcement.

Esposito said Delta is looking at Korean flights after completion of the new airport “because the Asian market here is fairly large.”

Delta once offered nonstop flights from Salt Lake City to Tokyo, but said the route failed largely because it then offered few connecting flights from there to other parts of Asia.

But Delta now has a partnership with Korean Air, and “they have about 50 unique destinations beyond Seoul” for connections, Esposito said.

Delta already offers nonstop international flights from Salt Lake City to many cities in Canada and Mexico, plus Amsterdam, Paris and seasonal service to London.

He said Delta is well positioned for continuing growth at its Salt Lake City operations because it has been investing in improvements here and in Los Angeles and Seattle — creating an improved net of service he said can capture a bigger share of air travel in the West.

He noted that 14 Mountain West destinations served by Delta may be reached only through Salt Lake City. That plus its 10 current international destinations, 11 destinations added last year and its total 300 flights daily to 100 cities is “really making Salt Lake City a great transit point for east or west, as well as international travel.”

Also, “On top of that, your market here in Salt Lake City has been rapidly growing,” where a strong economy has been creating many Utah passengers for Delta, Esposito said.

The airline is also trying to improve the types of aircraft serving Salt Lake City and their amenities, which he said may attract more business.

For example, he said 85% of Delta’s service here is now on large, mainstream aircraft. It is planning to retire most small 50-seat aircraft soon. Salt Lake City will be among the first to receive and use Delta’s new Airbus A220, which hold 110 passengers, will have the widest seats in the fleet with windows as large as on wide-body planes.

He said Delta also aims to offer seatback video and high-speed internet soon on all its flights.

Mayor Jackie Biskupski asked if the new planes also create less pollution — saying it is a concern of residents because it is building a bigger airport that may serve more planes “and we live in a valley.”

Esposito said the newer fleet is lighter and more fuel efficient, using less fuel per seat. He said Delta isn’t increasing flights out of Salt Lake City as much as it is increasing seats by offering larger, more efficient planes — which decreases overall pollution per seat.