Immigrants; is integration required?

In the past individual immigrants were forced to integrate into their host country to survive, language and culture were adopted and they were adopted into the land. With the modern influx of Immigrants and/or refugees that come in swathes of thousands, they now have the ability to create small communities. New immigrants join these communities because they share culture and language.

Should they be encouraged or even forced to integrate into their host country's culture and language or should they have the right to actively maintain their cultural identity, completely independent of the host country's culture? I live in Canada, it's ever present but not talked about here.

Please let me know your opinion, don't worry about being labeled based on your thoughts, that would be arbitrary and inappropriate