Delta Air Lines has announced it will end flights between Japan and Guam because of low demand just days after another airline delayed Japan-Guam flights because of North Korea's threat to attack the U.S. island territory.

Demand was not strong enough for Delta to maintain the route and the last flight will take place in January, said airline spokesman Hiroko Okada.

The carrier's decision leaves United Airlines as the only U.S. airline with flights between Guam and Japan. Japan Airlines also has flights from Narita airport to Guam.

Delta's decision came after HK Express delayed Japan-Guam flights until next summer, "citing geopolitical concerns in the region."

North Korean leader Kim Jong Un has threatened Guam. The country has fired two missiles over Japan including one launched on Friday.

Guam lost about $9.5 million in tourism sector spending in August because of the threats, the Guam Visitors Bureau said.

There were more than 7,000 cancellations of tours, school groups and business ventures mostly from Japan, the bureau said.