"The situation in Ukraine... is at a dramatic level," Prime Minister Jonas Gahr Store told journalists in Oslo.

"Yesterday was a turning point," he said, in reference to Russian President Vladimir Putin recognising the independence of two Ukrainian breakaway regions.

The premier was to travel to Brussels later on Tuesday, where he planned to have Norway join in the sanctions the bloc is imposing on Russia.

"It is important to react firmly to what has happened over the past day," he said.

Store also said that NATO's "Cold Response" military exercises will take place in the second half of March in Norway as previously planned.

Some 35,000 soldiers from 28 countries are due to participate in the biennial drills.

Moscow had been informed of the exercises and invited to send observers, as usual, Store said.