Suella Braverman has said some immigrants are “not embracing British values” and are living “parallel lives” to the rest of the country.
The Home Secretary, who has attracted criticism for suggesting multiculturalism has “failed”, said she would be “fearless” in identifying problems with integration.
She said there are “many towns and cities” where people from abroad are not learning English and “not taking part in British life”.
In a speech in the US last week, she attacked the “misguided dogma” of multiculturalism, saying it had “failed”.
Rishi Sunak declined to back her comments and former home secretary Dame Priti Patel suggested she may have said them simply to attract attention.
But on a visit to Bolton, Ms Braverman said: “It’s my job, first and foremost, to be honest and speak for the majority of the British people.
“And my comments have been somewhat mischaracterised.
“We have so much to be proud of. We have a great multi-ethnic society and in many parts of our country integration has worked.
“But there are also many towns and cities around the United Kingdom where it hasn’t and communities are living parallel lives.
“They are coming from abroad, they are not learning the language. They’re not embracing British values, and they’re not taking part in British life.
“And that needs to be identified, we must be fearless in calling that out and that’s my job.”
Conservative Party deputy chairman Lee Anderson told a fringe event he agreed multiculturalism had failed, adding: “Well, it depends… if you’re rich, if you come from a decent background, if you’ve got to university, if your family are businessmen, and you come from an ethnic background, then multiculturalism quite obviously has worked.
“Because you’ve got plenty of people from different backgrounds in Parliament, in positions – judges, lawyers, solicitors, brain surgeons, what have you.
“But if you come from the lower end of society where you live on a little terraced street in Derby or Nottingham where people haven’t lived together, where there’s people living on those streets who still can’t speak English after 20 years, then multiculturalism has not been a success.
“This is not about foreign people coming here and living in their own little communities and not integrating properly,” he said, adding “we see it with the Brits as well” and that he is aware of British people living in Spain who do not speak the language and who do not integrate with the wider community.
He added: “If you come and live in this country, you should live a British way of life, but it’s OK to retain your own country, that’s perfectly normal, but you should be British as well, and that’s not always happened.”