A motorcyclist has died after their motorbike collided with a truck on a busy road north of Brisbane on Monday afternoon.

Police warned motorists of "lengthy delays" after the crash, which occurred on Gympie Road at Strathpine, about 12:40pm.

Australian Traffic Network's Ben Mihan said Gympie Road was closed in both directions between Kremzow Road and South Pine Road.

Local diversions were in place, with delays backed up to Bald Hills on Gympie Arterial Road.

Paramedics tended to the critically injured motorcycle rider, who was believed to have died at the scene.

The truck driver was uninjured.