The centre-left government said in April it planned to increase Norway's defence budget by 83 percent over the next 12 years -- a rise of 600 billion kroner ($57 billion) -- calling its neighbour Russia "more dangerous, more unpredictable".

It proposed that Norway, a member of the NATO military alliance, order five new frigates, a fifth submarine, anti-air missiles, deep strike weapons, maritime surveillance drones and helicopters.

The minority government needed the opposition's support to move ahead with the plan.

On Tuesday, all parties represented in parliament, from the populist far-right to the small Communist party, backed the plan, albeit with a few modifications.

The main compromise involved the exercising of an option for a sixth submarine and the installation of an anti-air defence system to protect the Oslo region, similar to that in Washington.

"With six submarines, the navy will be able at any moment to have several submersibles on patrol simultaneously in Norwegian waters," said the opposition Conservative spokeswoman on defence affairs, Ine Eriksen Soreide.

"This will significantly increase dissuasion and surveillance capacities in Norwegian zones," she told reporters.

Norway and Russia share a 198-kilometre (123-mile) land border in the Arctic and a sea border in the Barents Sea.

Norway expects its defence budget to reach two percent of gross domestic product (GDP) this year, which is NATO's minimum target.