Defence Minister Phil Goff is seeking information about possible delays to ships being built under the $500 million Project Protector programme.
A spokesman for Mr Goff said he had asked the Defence Ministry to seek an explanation from contractor Tenix Defence over reported delays.
Last month Mr Goff attended the launch of New Zealand's first offshore patrol vessel, HMNZS Otago, in Melbourne.
The vessel remained in Australia for fitting out, trials and crew training and was due to be delivered and commissioned into service with the Royal New Zealand Navy in the second half of next year.
HMNZS Canterbury was launched in the Netherlands where it was built and was due to arrive in New Zealand in the first half of 2007.
However there had been some reports of delays which the Mr Goff's spokesman said needed to be clarified.
Mr Goff told National Radio he hoped there was no delay.
"Obviously we'd like to have the ships sooner rather than later but so far the project has been on time in terms of the construction and launching of those ships. The problem seems to be the final fitout and the training are taking a little longer than was originally anticipated."
Chief of Navy, Rear Admiral David Ledson said certainty was needed because of staffing issues.
"When we get these ships we will have a navy of 13 ships so we need to have the people for 13 ships and as a general rule on any one day 30 per cent of the uniformed people in the navy are under training, 30 per cent are ashore doing jobs and 30 per cent of them are at sea," he told National Radio.
"We know when we get these ships we have to get them to sea not to be able to do that is not really an option."
Under Project Protector the Navy will get seven new ships.