Canada strongly condemns the Kremlin’s actions off the coast of Crimea, said Foreign Affairs Minister Chrystia Freeland after Russian vessels fired on and seized three Ukrainian navy vessels in the Sea of Azov and Kerch Strait on Sunday.

“We call on Russia to immediately de-escalate, release the captured crew and vessels and not impede passage through the Kerch Strait,” Freeland said in a statement Monday.

Freeland said she spoke with her Ukrainian counterpart Pavlo Klimkin on Sunday and “assured him of Canada’s unwavering support for Ukraine’s sovereignty.”

Canada is also in contact with its G7 and NATO allies on this matter, she added.

“The Government of Canada is unequivocal in its support for Ukraine and in its condemnation of Russia’s illegal invasion and annexation of Crimea,” Freeland said. “Canada will always be a steadfast partner of the people of Ukraine, and we will continue to work with our allies to hold Russia to account for its unacceptable behaviour.”

Martial law declared

Ukraine’s parliament voted Monday to impose martial law in parts of the country to fight what its president called “growing aggression” from Moscow.

Russia and Ukraine blamed each other in the dispute that further ratcheted up tensions ever since Moscow annexed Crimea in 2014 and threw its weight behind separatists in eastern Ukraine with clandestine support, including troops and weapons.

Ukrainian President Petro Poroshenko asked lawmakers in Kyiv to institute martial law, something the country did not do even during the worst of the fighting in the east that has killed more than 10,000 people since 2014.

After a five-hour debate, parliament overwhelmingly approved his proposal, voting to impose martial law for 30 days starting Wednesday morning in 10 of Ukraine’s 27 regions — those bordering Russia, Belarus and Moldova’s pro-Moscow breakaway republic of Trans-Dniester.

The locations chosen were ones that Poroshenko identified as potentially in the front line of any Russian attack. The capital of Kyiv is not under martial law.

Poroshenko said it was necessary because of intelligence about “a highly serious threat of a ground operation against Ukraine.” He did not elaborate.

“Martial law doesn’t mean declaring a war,” he said. “It is introduced with the sole purpose of boosting Ukraine’s defense in the light of a growing aggression from Russia.”

Ukraine’s Defence Ministry already announced earlier in the day that its troops were on full combat alert in the country.

The approved measures included a partial mobilization and strengthening of air defences. It also contained vaguely worded steps such as “strengthening” anti-terrorism measures and “information security” that could curtail certain rights and freedoms.

Opposition denounces martial law

Poroshenko’s critics reacted to his call for martial law with suspicion, wondering why Sunday’s incident merited such a response. Poroshenko’s approval ratings have been plunging, and there were concerns that he would postpone a presidential election scheduled for March.

Just before the parliament met to vote, Poroshenko sought to allay those fears by releasing a statement revising his original martial law proposal from 60 days to just 30 days, in order to “do away with the pretexts for political speculation.”

Despite Poroshenko’s vow to respect individual rights, opposition lawmaker and former Prime Minister Yulia Tymoshenko warned before the vote that his proposal would lead to the possible illegal searches, invasion of privacy and curtailing of free speech.

“This means they will be breaking into the houses of Ukrainians and not those of the aggressor nation,” noted Tymoshenko, who is leading in various opinion polls. “They will be prying into personal mail, family affairs … In fact, everything that is written here is a destruction of the lives of Ukrainians.”

But Poroshenko insisted it was necessary because what happened in the Kerch Strait between Crimea and the Russian mainland “was no accident,” adding that “this was not the culmination of it yet.”

Naval confrontation

Russian coast guard ships fired on the Ukrainian navy vessels near the strait, which separates the Black Sea from the Sea of Azov, injuring six Ukrainian seamen and eventually seizing the vessels and their crews. It was the first open military confrontation between the two neighbors since the annexation of Crimea.

Ukraine said its vessels were heading to the Sea of Azov in line with international maritime rules, while Russia charged that they had failed to obtain permission to pass through the narrow strait that is spanned by a 19-kilometer (11.8-mile) bridge that Russia completed this year.

While a 2003 treaty designates the Kerch Strait and Sea of Azov as shared territorial waters, Russia has sought to assert greater control over the passage since the annexation.

At a U.N. Security Council meeting, U.S. Ambassador Nikki Haley urged Russia to “immediately cease its unlawful conduct” in the Black Sea.

In his first public remarks since the confrontation, President Donald Trump did not specifically call out Russia’s behaviour.

“We do not like what’s happening, either way, we don’t like what’s happening and hopefully it will get straightened out,” Trump said.

But Russia called Ukraine’s actions “dangerous.” Dmitry Polyanskiy, Russia’s first deputy permanent representative to the United Nations, told the Security Council the incident was another example of Ukrainian leaders trying to provoke Russia for political purposes.

“Russia has repeatedly warned the Kyiv regime and its Western patrons about the danger of inflating artificial hysteria in connection with the Sea of ​​Azov and the Kerch Strait,” said a statement by the Russian ministry of foreign affairs.

“Clearly, this is a well-thought-out provocation that took place in a predetermined place and form and is aimed at creating another hotbed of tension in that region and a pretext for stepping up sanctions against Russia.”

With files from The Associated Press