A cyclist has been killed while riding on a highway on the Mid North Coast of NSW.

The rider was struck by a truck in the southbound lanes of the Pacific Hwy at Buladelah about 6am on Monday.

Responding paramedics could not save the rider, who died at the crash site.

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They are yet to be formally identified.

The truck driver — a 58-year-old man — was taken to Manning Base Hospital at Taree for mandatory testing.

Southbound traffic on the Pacific Hwy is being diverted on Bulahdelah Wy through Bulahdelah, as emergency services and crash investigators remain are at the scene.

“This is suitable for all vehicles up to 26m B-doubles (GLM),” according to Live Traffic NSW.

Investigations are ongoing.