Minnesota's only nonstop flight to Asia could end soon, a Delta Air Lines executive warned Tuesday, a move that would make travel to the world's fastest-growing region more difficult for business travelers and vacationers.

Delta may be forced to cancel its daily flight from Minneapolis-St. Paul International Airport to Tokyo, which was started by Northwest Orient in 1947 and was the nation's first commercial air service to Japan, Ben Hirst, Delta's special counsel, told airport administrators.

The airline, which picked up the route along with a hub at Tokyo's Narita International Airport in its 2009 acquisition of Northwest Airlines, says those operations could "quickly unravel" if U.S. and Japanese transportation authorities approve an expansion of international routes at another Tokyo airport.

The proposed expansion, Hirst said at a meeting of the Metropolitan Airports Commission, would favor Delta rivals United Airlines and American Airlines, chiefly because they have partnerships with Japan's two major airlines. Delta's effort to develop a partnership with a smaller Japanese airline hasn't succeeded.

If the expansion of Tokyo's Haneda airport goes through, Delta would likely lose many Tokyo passengers to other carriers, making Narita unprofitable for the Atlanta-based airline, Hirst said. "It's not just parochial for Delta," he said. "It [affects] every point on the map that comes into and out of Narita."

He urged the commission to apply swift and aggressive pressure to the Minnesota congressional delegation and the U.S. Department of Transportation before the two governments meet again Feb. 9.

Commission members, who obtained a promise from Delta at the time of its acquisition of Northwest that international routes from MSP would be preserved, reacted strongly.

"The business community is asking for more Asia access, not less, so this a 180," said Rick King, a MAC commissioner who is an executive at Thomson Reuters in Eagan.

Jeff Hamiel, the airport commission's chief executive, said the demise of the route would hurt the state's businesses.

"Minnesota businesses need access to Asia," Hamiel said. "One of the reasons Minneapolis-St. Paul enjoys such a concentration of Fortune 500 companies … is because of connectivity to global markets, easy access to Europe and Asia. To jeopardize either direction, we in Minnesota are looking at significant impacts in our communities and potential loss of jobs. So this is one of those fights that I think it is worthwhile for the commission to become very aggressive in and participate in."

Narita was Tokyo's international airport for nearly four decades and suited Delta's needs when the other U.S. airlines also had to fly there. But its location — it is 46 miles from downtown Tokyo — is unpopular with many travelers.

When Narita opened, Haneda became a domestic airport.

Over the past 15 years, Japan has expanded Haneda and allowed international flights, building on its proximity to downtown Tokyo as well as the connections available there to other Japanese cities. U.S. flights have been restricted to nighttime, but Japanese and U.S. authorities are considering giving 10 daytime takeoff and landing slots — which travelers prefer — to U.S. carriers at Haneda.

Hirst said that Haneda needs to be completely opened with Delta given the option of moving its Tokyo hub to that airport from Narita. Splitting flights between the airports won't work without a Japanese partner, he said, because the hub needs passengers not just arriving in Tokyo but moving through it to other Asian cities.

If Delta's rivals expand at Haneda, they would likely take away enough of its Tokyo passengers from New York and Los Angeles to make those routes unprofitable, Hirst said. Without the passengers from those flights who connect at Narita to other Asian cities, Delta's flights to Tokyo from Minneapolis-St. Paul and Portland, Ore., would also start to lose money.

The MSP-Narita flight, which averages 89 percent capacity, could end within six months to a year.

"We think it will unravel fast," Hirst said. Only about 24 of the daily 250 passengers aboard the Narita flight from MSP begin their travel here. The rest come from across the country, chiefly other Midwest cities.

Sen. Amy Klobuchar said in a statement she spoke to Transportation Secretary Anthony Foxx about the issue.

Kristen Leigh Painter • 612-673-4767