The Conservative government's rhetoric on Ukraine could compromise Canada's efforts to resolve the protracted crisis, former prime minister Joe Clark says.

In an interview this week with The Globe and Mail, Mr. Clark called the government's comparisons to the Second World War "unhelpful," saying Ottawa should focus instead on the current situation in Ukraine. Mr. Clark is scheduled to deliver a keynote speech on Canadian foreign policy at an international development conference in Ottawa on Wednesday.

Earlier this year, Foreign Affairs Minister John Baird and Prime Minister Stephen Harper both compared Russia's annexation of Crimea to actions by Adolf Hitler in the leadup to the Second World War. Mr. Clark said he understands why the government has been outspoken on the matter, but added that he is concerned some of its statements could make it more difficult for Canada to participate in future negotiations.

Story continues below advertisement

"I think that the co-operation would have proved more effective without the rhetoric," he said. "I think there was a risk, there may still be a risk, that our rhetoric was so extreme that we will not be called to the influential decision-making meetings."

A spokesman for Mr. Baird said the minister makes "no apologies for the comparison," and noted that other leaders have also compared Russian President Vladimir Putin to Hitler.

Mr. Clark said he would not want to overstate Canada's potential role in helping to resolve the crisis, but said Canada is a skilled player with a reputation for moderation and for "keeping the lines open" – qualities he said could prove useful when it comes to Ukraine. "We have those skills, but we have to safeguard them. And the rhetoric, I think, raises the risk that we might not be as free to be helpful as we want to."

On Tuesday, Germany attempted to launch talks between the government in Kiev and pro-Russia separatists, a first step in implementing a "road map" developed by the Organization of Security and Co-operation in Europe. Acting Ukrainian Prime Minister Arseniy Yatsenyuk thanked the OSCE for the plan, but said Ukraine has its own "road map" for resolving the crisis.

Mr. Clark, who served as Canada's foreign minister in Brian Mulroney's Progressive Conservative government, said Ottawa is now "knocking on every door" to offer military and other help in dealing with Ukraine, a move he said is helping to take Canada beyond some of its earlier rhetoric.

Canada's military investment in the Ukraine crisis now includes the frigate HMCS Regina, six CF-18 fighter jets, one heavy lift plane, two Airbus transports and an estimated 250 military personnel in Romania. The government has also sanctioned dozens of Russian and Ukrainian individuals and companies and committed $220-million to a financial aid package for Ukraine. In addition, it will deploy a large election observer mission for the country's upcoming presidential vote.

With a report from The Associated Press