Mexican Ambassador Francisco Suárez is about to say adiós to Canada after a whirlwind two and a half years. But he has a tinge of regret about the timing.

“Everybody’s saying, ‘You’re leaving when we’re starting to have the best moment in [the] Canada-Mexico relationship,’” said the ambassador in an interview last week. “Where all the stars are well aligned into a nice constellation.”

Under Stephen Harper’s Conservatives, Mexico-Canada ties chilled. The Mexicans were miffed when Canada imposed a visa on their citizens in 2009 amid a growing number of refugee claims, so much so that Mexican President Enrique Peña Nieto nixed a planned visit to Canada and Mr. Suárez was famously quoted saying his country was “really mad” at the Harper government. Mr. Harper similarly kicked down the road a North American Leaders’ Summit planned for February.

But the Mexicans have been buoyed by Prime Minister Justin Trudeau’s new majority government. Mr. Trudeau has committed to soon lifting the visa on Mexican citizens travelling to Canada and he’s promising renewed focus on Canada-United States-Mexico ties. Mr. Suárez said he expected the so-called Three Amigos summit to take place in Canada next year, possibly in the spring though a date is undecided.

The Mexican Embassy helped facilitate a midnight phone call from Mexico’s president to Mr. Trudeau on election night, and the two then met at the recent G20 meeting in Turkey and APEC summit in Manila (where social media users had them competing for the title of #APEChottie).

“So it started with a splash, huh?” said the always-quotable former politician, who was appointed to be ambassador by President Peña Nieto, who shares the same party colours. Before coming to Canada, he headed a party think tank, served twice as a federal congressmen and was his country’s ambassador to the OECD.

Mr. Suárez, 72, is set to leave Ottawa on Dec. 5 and retire after “45 years of uninterrupted public service.”

While in Canada, he had a couple sons in the country, one working for Scotiabank in Toronto and another attending Ashbury College in Ottawa. Both have since gone back to Mexico along with two of his grandchildren who were born in Canada.

He expects in early January to give his last report on Mexico-Canada ties to headquarters at a meeting of Mexican ambassadors and then finish his duties.

Though that doesn’t mean he’ll keep quiet. The tall, jovial ambassador hopes to restart a biweekly opinion column he used to write for the newspaper El Universal, finish his memoirs (“notes of my public life” in his words, because “I like to be low-key”) and lecture at conferences and schools.

Though the visas got all the media attention, Mr. Suárez is fond of noting that Canada-Mexico ties are about more than just one issue. The two have worked together notably on energy, infrastructure and trade. On the latter, they joined forces to fight United States food labelling rules and again to get a better deal for their auto industries from the Trans-Pacific Partnership.

Helping to push Mexico-Canada and North American ties, the ambassador credits several “trilateralist crusaders,” including former Canadian Council of Chief Executives head Thomas d’Aquino and the group’s current president John Manley and top staffer Eric Miller, former diplomat Colin Robertson, Canadian Manufacturers and Exporters chief Jayson Myers and Globe and Mail columnist Jeffrey Simpson, among others.

His successor is expected to be Mexican Ambassador to France Agustín García-López, though as of last week he still needed to be confirmed by the Mexican Senate. Mr. Suárez worked with him at the OECD.

One piece of advice to Mr. García-López and his wife, besides the normal “get out of Ottawa” refrain: “don’t stop the zumba!”

Every Thursday at 9 a.m., the current ambassador’s wife, Diana Mogollon de Suárez, hosted more than a dozen other wives of ambassadors for zumba class (a kind of aerobics) in the basement of the couple’s residence, taught by a professional teacher. It’s been a great networking opportunity and a chance to get to know others in the diplomatic corps, he noted.

An economic specialist, the ambassador jokingly modified a quote from the famed father of economics Adam Smith: “whenever we have more than five zumba ladies gathering, they always meet to conspire against their husbands.”