"We will work closely with emergency services to look at what we can do to prevent environmental damage in the wake of this accident," said Mr Dragten.
NZTA said the road is down to one-lane this morning, but will be closed at intervals this afternoon as a crane is used to remove the truck in three sections.
Highway network operations manager, Karen Boyt, said the only alternative route is via SH4 to Wanganui.
"This could add significantly to journey times depending on people's destinations - so motorists may instead prefer to plan their journey to avoid the closure period or to wait at Awakino and go through when the road reopens between each operation," Ms Boyt said.
The crash comes less than 24 hours after a fatal truck crash on the Desert Road where a small amount of toxic chemicals spilled into the Waihohonu Stream.
- nzherald.co.nz and Newstalk ZB
