How is the term melting pot different from the Canadian idea of cultural mosaic?

"melting Pot" is used in the USA because it is expected for all the new immigrants to blend together to make it one country, one language under one law and government which of course is a great idea but does not always work.

Cultural mosaic in Canada is that people hold on to their own traditions, their own way of dress etc. this does not always work either, most people in Canada would also like immigrants to blend and adopt Canada's way of life, so this is also a question for discussion and debate.