Ottawa Mayor Larry O'Brien said it's important not to "knee jerk" after Prime Minister Stephen Harper announced Friday that 550 jobs would be moved from the federal capital to a city in New Brunswick.

In an interview with CTV Ottawa, O'Brien said the city has not decided what to do yet in the wake of the surprise announcement, which drew fire from the country's two largest public service unions.

'We need to be balanced'

"We haven't yet defined what the overall impact will be on the city, but obviously when you lose 500 jobs ... that's bad news," O'Brien said.

But he pointed to 1996, when he said 15,000 jobs were cut from the public service in Ottawa and the city ended up posting a net gain in the next two years.

Moreover, 10 to 15 per cent of public servants will retire in the next decade, and with most expecting to stay in Ottawa O'Brien said the city would look to newcomers to fill the gap.

"I think we need to be balanced and thoughtful in this and let the federal government get on with its business."

Surprise announcement to balance gun-registry decommissioning

Harper's suprise announcment in Miramichi, N.B was to compensate the town for the possible closure of the long-gun registry, which employed about 200 people.

"Let me assure you, the jobs we're creating at this announcement today will absorb any job losses in the firearms centre many times over," Harper told a news conference.

Move expected to save money

The public service unions said that annoucement came out of the blue, and added it's just more evidence that the Harper government is a shoddy employer.

Harper estimated it would cost almost $300 million during the next six years to consolidate the payroll system, but added that once it is completed, it would save about $80 million.

When Parliament resumes in a few weeks, members will debate a Conservative private member's bill to eliminate the registry, if passed.

With files from The Canadian Press