A Russian military plane circled over a Canadian frigate on a NATO mission in the Black Sea, a maneuver Ottawa denounced Monday as "unnecessarily provocative."

The Russian aircraft "did not in any way pose a threat to the Canadian ship," said Canadian Defense Minister Rob Nicholson.

However, "their actions were unnecessarily provocative and risk escalating tensions even further" in the region, he said.

The HMCS Toronto left Canada's Atlantic coast at the end of July with 250 sailors and Sea King helicopters on board to join the NATO mission.

"The participation of HMCS Toronto in NATO's reassurance measures in the Black Sea demonstrates Canada's steadfast commitment to peace and security in Eastern and Central Europe," the Canadian defense minister said.

These measures have been undertaken "as a direct result of the Putin regime's military aggression and invasion of Ukraine," he said.

Canada and NATO forces are sending the message that "Russia's reckless actions must stop," he added.

Earlier Monday, Canadian Foreign Affairs Minister John Baird had indicated that Canada was ready to impose fresh sanctions against Russia aimed at pressuring President Vladimir Putin over Moscow's role both in eastern Ukraine and Crimea.