An escalating diplomatic dispute between Canada and Saudi Arabia showed no signs of fizzling out Wednesday as the prime minister refused to offer an apology to end it.

Speaking to reporters in Montreal, Prime Minister Justin Trudeau defended Canada’s actions and stood behind a tweet sent out by Global Affairs Canada condemning the recent arrests of social activists, including the sister of blogger Raif Badawi, whose wife and three children recently became Canadian citizens.

Trudeau said Canada will always speak “strongly” about concerns around human rights.

“There’s no secret that Canada speaks firmly about its values around the world,” he said in French, noting that has long been this country’s approach to its relations with Saudi Arabia.

Saudi officials have demanded Canada apologize for the tweet, calling it a “big mistake.”

Bessma Momani, a top Canadian expert on Saudi relations, interpreted that as asking for either a “public and formal apology or the resignation of our [foreign minister].”

On Sunday, the Islamic Kingdom expelled Canada’s ambassador from the country, recalled its own, suspended all international trade with Canada and recalled its foreign students.

Since then, Saudi Arabia has halted wheat and barley trade, suspended medical treatments for Saudi patients in Canadian hospitals, and reportedly told its central bank and public pension firms to sell off its Canadian assets.

Trudeau said Canadians expect their country to be a leader on the world stage, a role which includes defending human rights. As for diplomatic discussions, they will always be conducted in a “constructive and polite way.”

He said Foreign Affairs Minister Chrystia Freeland had a long conversation with her Saudi counterpart on Tuesday. Canada has also engaged directly with several other nations about the diplomatic spat. Reuters reported Canada was seeking help from Britain and the United Arab Emirates.

Asked about the United States’ decision to remain neutral in all of this, Trudeau said he was “never going to impose on another country what their reaction or their response should be.”

Other countries, should be allowed to “speak for themselves.”

As for using social media to convey its message, the prime minister said the Canadian government will continue to use all platforms and tools available to it – including social media like Facebook and Twitter.

At least one former Canadian diplomat has criticized Canada’s decision to engage in formal diplomacy on Twitter. Colin Robertson told The Canadian Press the current row is the result of “diplomacy by tweet.”

“We are becoming too carefree with tweets,” he said.