Russia's ambassador to Canada downplayed a recent series of diplomatic expulsions and referred to a Canadian attaché newly booted from Moscow as a "military spy" after a speech in Toronto Tuesday.

The expulsions, along with trade and economic sanctions, are related to diplomatic efforts to stop Russia from meddling in the months-long Ukraine conflict that has seen Russia annex Crimea.

"Canadians expelled our guy, military attaché, so it's probably we also kicked out some military spy from Moscow. Simple stuff. Nothing relevant in my line of job when I discuss serious security issues," Georgiy Mamedov told an audience following a speech at the Empire Club.

On Tuesday, Russia expelled a Canadian diplomat from Moscow in retaliation for Ottawa kicking out a Russian military attaché earlier this month.

Margarita Atanasov, a Canadian first secretary working in the immigration section, was told she was being booted from Russia on the same day set as the deadline for Lt.-Col. Yury Bezler, an assistant military attaché at the Russian Embassy in Ottawa, to leave Canada.​

It's the latest in a tit-for-tat diplomatic fight amid the intensifying conflict over Ukraine — a point Mamedov made during his speech and question and answer session Tuesday.

Mamedov compared the stand-off with Canada to penalties in playoff hockey, and told the audience that there's "a certain diplomatic dance" with sanctions and expelled diplomats "where everybody reciprocates."

'Badmouthing everybody'

On April 8, the Canadian government quietly ordered a Russian diplomat to leave the country in retaliation for a Canadian envoy's expulsion from Moscow two weeks earlier, the CBC's Hannah Thibedeau reported.

At the same time, Canada's ambassador to Russia returned to his post in Moscow. John Kur had been recalled by Prime Minister Stephen Harper more than a month before to protest Russia's actions in Ukraine.

A protester holds a sign as Russian Ambassador Georgiy Mamedov delivers a speech on 'Russia, Ukraine and Crimea - The Russian Perspective' to the Empire Club of Canada in Toronto Tuesday. (Chris Young/Canadian Press) The original dispute started earlier when the Russian government requested accreditation for a handful of diplomats to come to Canada. The Canadian government denied the visas because officials did not believe they were filling the roles they claimed, sources told CBC News. Following that decision, a diplomat at the Canadian Embassy in Moscow was told by the Russians he was no longer welcome.

Mamedov had harsh words for the Conservative government, advising it to join the international community in working with Russia and Ukraine rather than sitting on the sidelines.

"I told them, if you want to be serious players, if you want to help Ukrainians, if you want to be instrumental in national reconciliation in Ukraine, join the group. Be with us, Americans, European Union, yes we argue, but we are trying to do something. It's much harder than just standing on the sidelines and badmouthing everybody," Mamedov said, telling the audience that he's summoned regularly for dressing-downs at Foreign Affairs.

A spokesman for Foreign Affairs Minister John Baird didn't directly address most of Mamedov's criticism, but threatened to "further isolate" Russia politically and economically.

"We find it strange that the ambassador once said that Russian troops would never invade Crimea, only to be fantastically disproven by his own president, who last week confirmed this," Adam Hodge said in a statement.

"Canada calls on Russia to follow through on its Geneva commitments to de-escalate the crisis, to respect Ukraine’s territorial integrity and to cease its interference in a sovereign state. These provocative actions must stop, and Russia must respect the sovereignty and territorial integrity of Ukraine. Anything short of this will be completely unacceptable.​"

Ambassador heckled

The Russian ambassador also said it was "deeply offensive" that Baird compared Russia's occupation of Crimea to Nazi Germany's annexation of Sudetenland in the former Czechoslovakia in 1938.

Mamedov told the Toronto audience that Russia wants a united Ukraine.

"There is a lot of talk about Russian troops on the border with Ukraine. Of course we are concerned because Ukraine is on the brink of civil war," he said.

Mamedov said Russian troops are on the border to prevent extremists from taking vengeance on Russian-speaking Ukrainians.

"Will we use them? I can give you my personal assurances: our troops won't cross [the] Ukrainian border," he said. "It's the last thing we want. It will be disaster. Not for [the] world community. Not only for people in Canada who feel deeply about Ukraine. It will be total disaster for Russian identity, historic and otherwise."

The ambassador was heckled several times as he started his speech, but he persevered, asking the crowd not to throw pies at him. The audience included representatives from the Ukrainian-Canadian community, who used the question and answer session following the speech to point to differences between reports from the region and Mamedov's take on events.

The speech comes the same day U.S. Vice-President Joe Biden warned Russia that "it's time to stop talking and start acting" to reduce tension in Ukraine.

The crisis dates back to last November, when then President Viktor Yanukovych reversed a pro-EU trade deal. Tensions boiled over in February when Yanukovych cracked down on protesters and he was ousted. He has taken refuge in Russia, the country that annexed Ukraine's Crimea region.

Mamedov has been Russia’s ambassador to Canada since 2003.

A spokesman for Stephen Harper said the prime minister spoke to Moldova's Prime Minister Iurie Leanca on Tuesday. The two leaders "strongly condemned Russia’s unprovoked violation of Ukrainian sovereignty and territorial integrity," Jason MacDonald said in a statement.

"Prime Minister Harper took the opportunity to reaffirm the importance of Moldova's sovereignty within its internationally recognized borders."