Flight across the country have been grounded due to a radar issue.

AirWays New Zealand says there is an issue with the air traffic control system which is affecting flights.

In a tweet the company says they are aware of the issue, and back-up procedures are in place.

Christchurch Airport said planes have been grounded "across the country" as a result.

Apologies for delays to your travel at the moment. Planes have been grounded at airports all over the country as a result of an issue for @AirwaysNZ, which manages air traffic control.

— Christchurch Airport (@CHC_Airport) September 30, 2019