Prime Minister Stephen Harper is calling on Russian President Vladimir Putin to withdraw his military forces from Ukraine and "refrain from further provocative and dangerous actions."

Harper issued the statement Saturday, after meeting with some of his cabinet ministers and speaking with U.S. President Barack Obama.

"We join our allies in condemning in the strongest terms President Putin’s military intervention in Ukraine. These actions are a clear violation of Ukraine’s sovereignty and territorial integrity. They are also in violation of Russia’s obligations under international law," Harper said.

The situation in Ukraine escalated earlier Saturday, when Putin won the approval of Russian lawmakers to use military force in Ukraine, moving to formalize troop deployments that Ukrainian officials have called an ongoing invasion of the strategic region of Crimea, where Russia controls a naval base in the capital of Sevastopol.

Images from Ukraine on Friday, showed that unidentified troops had already begun patrolling areas in Crimea. On Saturday, Ukrainian ambassador to the United Nations, Yuriy Sergeyev, said that more than 16,000 Russian troops had moved into the region.

"And their numbers are increasing every coming hour. This action by the Russian Federation constitutes an act of aggression against the state of Ukraine," Sergeyev said. "It’s a violation of international law, posing a serious threat to the sovereignty and territorial integrity of our country, as well as peace and stability in the whole region."

Sergeyev called on the UN Security Council to stop Russian aggression.

Meanwhile, Canada’s Department of Foreign Affairs says Canadians should not travel to Crimea, a region in the southern part of Ukraine that’s currently the main flashpoint of the crisis. The department said Canadians presently in the region should consider leaving “while it is safe to do so.”

Harper also said on Saturday that Canada has suspended its preparations to attend June’s G8 Summit in Sochi, the Russian city that recently hosted the Olympics. Harper added that the Canadian ambassador in Moscow is being recalled for consultations.

"Canada supports the immediate deployment of international monitors from the United Nations and the Organization for Security and Cooperation in Europe to Ukraine," Harper said. "We will continue to cooperate closely with our G-7 partners and other allies. Should President Putin continue on this course of action, it will lead to ongoing negative consequences for our bilateral relationship."

Employment and Social Development Minister Jason Kenney said he would not speculate on what economic sanctions Canada might take against Russia in the coming days. But he did say that Canadian officials continue to discuss with world leaders about what “tools” are available.

“We will continue to work with our Western allies in supporting Ukraine’s territorial integrity,” Kenney said in an interview to be broadcast on CTV’s Question Period Sunday. “And I don’t think we’re ruling out any options at this point as to how we do that.”

Crimea, with a large Russian-speaking population, remains largely loyal to ousted Ukrainian President Viktor Yanukovych. The fugitive president, who has fled to southern Russia, pledged Friday to fight for his country's future but said he will not ask for military assistance.

With files from The Canadian Press and The Associated Press