The Navy has begun the second phase of its $58 million upgrade of frigates Te Kaha and Te Mana.
Defence Minister Wayne Mapp says the systems upgrade will improve the performance and extend the range of conditions in which the frigates are effective.
It will also allow the Navy to use technology developments made over the past 20 years, he says.
The upgrade work will be carried out in New Zealand, Australia, Canada, and Germany.
