A Korean Air passenger jet has made an emergency landing at a Canadian military base after a bomb threat was made against the flight, officials and the airline said.

Tuesday's diversion came after the airline's call centre in Los Angeles received an anonymous call saying a bomb had been planted aboard the South Korean flag carrier's flight from Vancouver to Seoul.

The Boeing 777, with 134 passengers, and 12 crew, was diverted to the Comox base on Vancouver Island after the call was received 25 minutes into its flight.

The plane landed without incident and was undergoing safety checks, the airline said.

"The airline will decide about the continuation of the flight after discussion with the airport and related authorities," Korean Air said.

The North American Aerospace Defense Command (NORAD) said two US F-15 fighters were scrambled out of Portland, Oregon to intercept the plane "due to a potential threat associated with the aircraft".

"The Korean Airliner was intercepted, diverted and the aircraft was shadowed until it landed at Canadian Forces Base Comox," NORAD said in a statement.