Prime Minister Justin Trudeau is condemning Russia's attack on Ukraine and calling on Russian President Vladimir Putin to withdraw all military forces from the country.

"Canada condemns in the strongest possible terms Russia’s egregious attack on Ukraine," Trudeau said in a statement late Wednesday.

"These unprovoked actions are a clear further violation of Ukraine's sovereignty and territorial integrity. They are also in violation of Russia’s obligations under international law and the Charter of the United Nations." 

Trudeau said Russia’s actions will be met with severe consequences. 

Trudeau said he would be meeting Thursday with G7 partners and would work quickly with NATO and Canada's allies "to collectively respond to these reckless and dangerous acts, including by imposing significant sanctions in addition to those already announced." 

"Ukraine’s sovereignty and territorial integrity must be respected and the Ukrainian people must be free to determine their own future." 

Bob Rae, Canada's ambassador to the United Nations, called the attack "a grotesque war crime." 

"Putin is the cause of all this. We cannot let him win," Rae said on Twitter. "C’mon people, stop pretending. War has started." 

Rae went on to call what is happening "brutal thuggery." 

"Unprovoked, evil, aggression. From a permanent member of the Security Council, during a meeting of the Security Council of the United Nations." 

Foreign Affairs Minister Melanie Joly said she has spoken with Canada's ambassador to Ukraine, Larisa Galadza.

"The team is safe and the embassy will offer consular services to Canadians from Lviv as long as possible," Joly said on Twitter. "If you need consular help in Ukraine, please reach us at sos@international.gc.ca."

Updated travel advice for Canadians in Ukraine warned, however, that the government's ability to provide consular services in Ukraine could become "severely limited," and that Canadians should not rely on the government to help them leave the country.

"If you are in Ukraine, you should shelter in place unless it is safe for you to leave the country," the updated guidance said.

Those who choose to remain should "monitor trustworthy news sources to stay informed on the evolving situation" and follow instructions from local authorities, it said.

Eugene Lupynis with Metro Vancouver’s Ukrainian Community Society Of Ivan Franko said the news about the invasion has left him full of terror and concern. 

"We’ve been watching this build not just for weeks but for years," he said in an interview. "When Russia invaded Crimea and eastern Ukraine back in 2014, there was always a feeling something would happen but we were praying it wouldn't." 

Lupynis’ immediate family moved to B.C. in the 1950s but he has many relatives living in western Ukraine. He said the invasion "boggles the mind" and that everyone needs to fear what Putin could do next. 

“The West has always underestimated what Putin could, and would, do … he’s rewriting history in his own pen and trying to get the world to believe it." 

Former Conservative prime minister Stephen Harper issued a statement on Twitter, saying he prays for the people of Ukraine, and that the invasion is a long time coming.

"Putin's war on Ukraine began in 2014," the statement reads. "This full scale attack, unleashing death and horror on a mass scale, merely makes explicit what he has long planned."

Calling for NATO allies to "stand ready to honour their full treaty commitments," Harper wrote "Putin and his gang must be treated like the full global pariahs they have chosen to become. They must be sanctioned, excluded and punished at every turn."

Alberta Premier Jason Kenney called the invasion "devastating," tweeting "Weakness invites aggression. The democratic world must be united in standing with Ukraine. That should begin with a hard global embargo of all Russian oil & gas exports." 

The Ukrainian Canadian Congress Alberta Provincial Council issued a statement saying more than 330 000 people in Alberta claim Ukrainian ancestry, and called for Albertans to support Ukraine "militarily, politically, economically and financially."

Manitoba Premier Heather Stefanson tweeted that her province joined the federal government in calling on Russia to end its invasion, writing "It's hard to imagine how difficult watching the news must be for so many Manitobans who have loved ones in Ukraine."

Former Conservative MP James Moore called on the federal government to table a motion in Parliament to expel Russian Ambassador Oleg V. Stepanov.

Putin warned other countries Wednesday that any attempt to interfere with the Russian military action would lead to “consequences they have never seen.” 

He said the attack was needed to protect civilians in eastern Ukraine – a claim the U.S. had predicted he would falsely make to justify an invasion. 

In a televised address, Putin accused the U.S. and its allies of ignoring Russia’s demand to prevent Ukraine from joining NATO and offer Moscow security guarantees. He said Russia's goal was not to occupy Ukraine. 

As Putin spoke, big explosions were heard in Kyiv, Kharkiv and other areas of Ukraine. 

U.S. President Joe Biden denounced the “unprovoked and unjustified” attack on Ukraine and said the world will “hold Russia accountable.” 

A full-blown Russian invasion could cause massive casualties and topple Ukraine’s democratically elected government. And the consequences of the conflict and resulting sanctions levied on Russia could reverberate throughout the world, affecting energy supplies in Europe, jolting global financial markets and threatening the post-Cold War balance on the continent. 

Putin said the Russian military operation aims to ensure a “demilitarization” of Ukraine. He urged Ukrainian servicemen to “immediately put down arms and go home.” 

Putin announced the military operation after the Kremlin said rebels in eastern Ukraine asked Russia for military assistance to help fend off Ukrainian “aggression." The announcement immediately fuelled fears that Moscow was offering up a pretext for war, just as the West had warned. 

A short time later, the Ukrainian president rejected Moscow’s claims that his country poses a threat to Russia and said a Russian invasion would cost tens of thousands of lives. 

“The people of Ukraine and the government of Ukraine want peace,” President Volodymyr Zelenskyy said in an emotional overnight address, speaking in Russian in a direct appeal to Russian citizens. “But if we come under attack, if we face an attempt to take away our country, our freedom, our lives and lives of our children, we will defend ourselves. When you attack us, you will see our faces, not our backs.” 

Zelenskyy said he asked to arrange a call with Putin late Wednesday, but the Kremlin did not respond. 

In an apparent reference to Putin’s move to authorize the deployment of the Russian military to “maintain peace” in eastern Ukraine, Zelensky warned that “this step could mark the start of a big war on the European continent.” 

"Any provocation, any spark could trigger a blaze that will destroy everything,” he said. 

-- With files from Nick Wells, AP