Traffic is backed up as over the Habour Bridge following a truck breakdown this afternoon.

A truck has broken down on State Highway 2/Takitimu Drive at the Elizabeth Street roundabout.

NZTA says due to the incident "all lanes are currently blocked".

A caller to the 0800 SUNLIVE news hotline says traffic is backed up as far as the Mount Maunganui side of the Harbour Bridge.

SunLive understands a mechanic has been called to the breakdown.

Motorists are advised to expect delays.