Prime Minister Justin Trudeau said today that, while there have been "interesting moments" in Canada's relationship with the United States in recent years, he was not mocking U.S. President Donald Trump at the recent NATO summit when he was caught on camera speaking privately with other NATO leaders.

Trudeau told CBC News Network's Power & Politics host Vassy Kapelos in a year-end interview airing today that he was simply talking about how the day went at the recent summit in the U.K.

"We were talking about whether the president was going to be late for this event. I said, well he does press conferences, that I'm happy to be part of ... so it's possible he's going to be running late," Trudeau said in an interview filmed earlier today in Montreal.

"And, oh, by the way, in [my photo op with Trump] ... he announced that we're going to Camp David [for the 2020 G7 summit] and it surprised his advisers."

Asked if he was shocked when Trump called Trudeau "two-faced" after seeing the video, the prime minister said that, despite their differences, they still manage to work together.

"I think we've been through some interesting moments in terms of the relationship with the president before," Trudeau said. Despite that, he added, "we were able, just a few days later, to talk about the ratification, or the approaching signing, of the new NAFTA.

"We're staying focused on the big things, despite the other things."

Trudeau was pressed about persistent rumours that he has asked former interim Conservative leader Rona Ambrose to take over from the retiring David MacNaughton as Canada's next ambassador to the U.S. "No, I haven't asked her," he replied.

Trudeau said Ambrose — now being talked about in Conservative circles as a replacement for outgoing Conservative leader Andrew Scheer — "did a very good job on our NAFTA panel and has had some reflections to make about what she wants in her future, and I wish her well."

Prime Minister Justin Trudeau reveals whether or not he has asked the former Conservative leader to be his ambassador in Washington. 2:13

Trudeau said he's confident the House of Commons will vote to ratify the revised NAFTA trade pact and his government will work to get the deal passed "as quickly as we can."

"A lot will depend on the other parties in the House," he said. "We're reasonably comfortable that we're going to have the support to pass it because the Conservatives were in agreement and approval of it last year, even before we got all the improvements we got to it through working with the Democrats.

The House of Representatives held its vote on NAFTA today, passing it on to the U.S. Senate.

If Canada only ever spoke with countries who share our values we'd only talk to like six countries around the world. - Prime Minister Justin Trudeau

That vote came a day after the House of Representatives voted to impeach Trump for abuse of power and obstructing Congress. The charges stem from allegations that Trump withheld military aid from Ukraine to pressure it to open an investigation into the son of Joe Biden, the leading Democrat in the race to unseat Trump in 2020.

Trudeau refused to comment on the impeachment process, saying that he doesn't "engage on the domestic side" of U.S. politics because his job is to "stand up for Canada's interests."

Asked if he would ever ask a foreign country to investigate Scheer, the prime minister said he has not and would not.

Free trade with China

While Trudeau touted the revamped NAFTA, he all but dismissed the notion that Canada could strike a similar deal with China any time soon.

"I think we're a long way from that," he said. "I think there is a role that Canada can play in helping China understand and play, perhaps in a more positive way, according to the international rules-based order.

"But China will make its own decisions. And until there is room to find that common ground, I don't think that greater free trade with China is really something we can explore."

Trudeau said Canada's relationship with China is complex but is currently dominated by China's detention of Canadians Michael Kovrig and Michael Spavor.

'These two Canadians that have been unfairly detained need to be returned home.' 4:47

"I think in some ways there is an adversarial context in that we want them to release those Canadians who've been unfairly detained," he said. "In other areas, we're able to work on trade and work through issues, like the beef and pork issue we were able to resolve this summer."

Asked if Canada should pursue any expansion of trade with China when Beijing seems to be violating human rights in Hong Kong and through its treatment of the Muslim minority Uighurs, Trudeau said Canada can't afford to be too selective about the countries with which it engages.

"If Canada only ever spoke with countries who share our values, we'd only talk to, like, six countries around the world," he said.

"China is a really important market for many of our natural resources. We just have to be careful, as we always have, that as we engage, we stay strong on standing up for human rights."

Prime Minister Justin Trudeau spoke about national unity, Canada-U.S. relations, the fraught relationship with China and the two Canadians detained there in a year-end interview with Power & Politics host Vassy Kapelos. (Brennan MacDonald/CBC)

Trudeau said that concerns about China's human rights record helped to sink the prospect of trade negotiations with the rising superpower shortly after he came to office.

"Look at the NAFTA principle ... of signing labour deals with Mexico to bring up the quality of life and the quality of labour conditions for workers in Mexico," he said. "That is one of the goals, one of the side benefits, of having trade agreements with countries who have very different approaches, or resources, or even standards than us."

Trudeau said initial attempts to bring up those issues with China did not work out the way they did with Mexico.

"They were resistant to it. And that was one of the reasons we realized, 'Okay, maybe there's not a path for a greater trade agreement right now.'"

Canada's former ambassador to China, David Mulroney, told CBC News that approaching Beijing with a progressive trade agreement with the goal of changing China's behaviour might be a fruitless effort.

"I was encouraged when he said a free trade deal would be some way off. That's realistic and he probably needs to say nothing more than that. But he shouldn't tack on the idea that if we could do a free trade deal, it would be liberalizing like the one we did with Mexico, because that is a misreading of China," Mulroney said.

Watch the full interview with Prime Minister Justin Trudeau in the player below: