The Navy is preparing to ship nearly 140 staff to Canada.

The crew of the HMNZS Te Kaha, one of two Navy frigates receiving combat upgrades in Canada, are planning to join their frigate next week once granted clearance by Canadian authorities.

Canada has counted 93,157 cases of Covid-19 and 7637 deaths, has closed its border to "non-discretionary" travel, and requires anyone entering the country to self-isolate for 14 days.

A Defence Force spokeswoman, in a statement, said the Navy crew will prepare the Te Kaha for trials on the sea, and will return the vessels to New Zealand.

"Defence is working with the Canadian Government on the entry requirements, including the requirement to self isolate for 14 days upon arrival. We do not yet have confirmation of the entry requirements," the spokeswoman said.

The Navy had 69 staff return from Canada in March as Covid-19 began to spread across the world. The spokeswoman said a number of staff remained in the country to continue essential work, but did not specify how many.

"All Navy and Ministry of Defence personnel will observe all relevant local Covid-19 regulations in returning to Canada, staying in Canada, or upon return to New Zealand," the spokeswoman said.

The Te Kaha has been in Canada since 2018, receiving upgrades on its missiles, anti-ship missile decoys, sonar and underwater telephone, and torpedo defence system.

The upgrades for the two frigates was budgeted at $446 million in 2014, with another $148m committed to the project in 2017.