MONTREAL -- Prime Minister Justin Trudeau used the example of Italian grandmothers in Montreal on Thursday to explain why Canadians shouldn't be "overly impatient" with the integration of newcomers.

Being fearful of immigrants is "nothing new" in Canada and around the world, he said, explaining that Italians and Greeks settling in Montreal in the 1950s faced similar kinds of discrimination as do Muslims and other immigrants today.

"The first generation is always going to have challenges in integrating," Trudeau said during a panel discussion with London Mayor Sadiq Khan.

"There are districts (in Montreal) where Italian grandmothers still pretty much only speak Italian and don't speak that much French or English. But their kids and grandkids are seamlessly and completely integrated into Montreal and the only difference is they tend to be trilingual and not just bilingual."

The prime minister was taking part in a day-long conference hosted by Canada 2020, which describes itself as a progressive think-tank.

Asked by the panel moderator what can be done to reduce fear of and discrimination against newcomers, Trudeau replied that what's happening in Canada and around the world is "nothing new."

Italians and Greeks who settled in the northern part of Montreal and in other Canadian cities "faced tremendous discrimination, tremendous distrust."

"This country didn't happen by accident," Trudeau continued. "And it won't continue without effort. When we think about integration and success we can't be overly impatient."

He said citizens should "keep a solid pressure" to ensure human rights and the country's Charter of Rights and Freedoms are respected by all Canadians.

Trudeau also referred to his time visiting places of worship around the country such as mosques and temples.

He was recently criticized online and in some Canadian media for visiting a mosque in Ottawa where women and men were kept separate.

The prime minister said Canadians should engage with all communities.

"The question is, do you engage or participate or say 'I'm not going to talk to you until you hit the norm or the perfect ideal that we all aspire to'," he said. "I think (the latter) is wrong."

Khan said Canada "has become a beacon of how a civilized G7 country should treat those who are vulnerable and need help."

He also praised Trudeau for his "progressive" politics and said the prime minister's election in October 2015 inspired him.