The home secretary, Sajid Javid, has defended calling a convicted sexual grooming gang “sick Asian paedophiles”, arguing that noting the ethnicity of the perpetrators was a key element in tackling such crimes.

Discussing wider issues of immigration on BBC Radio 4’s Today programme, Javid said his comments in a tweet in October, which prompted condemnation from other MPs, were “absolutely appropriate” and did not demonise immigrants.

Referring to the conviction of a grooming gang in Huddersfield that raped and abused girls as young as 11, Javid tweeted: “These sick Asian paedophiles are finally facing justice.”

Asked whether such a sentiment indicated he was the sort of home secretary who preferred to play on people’s anxieties, rather than welcome immigrants, Javid said: “I don’t think there’s a choice, if you look at both of those.”

He said: “First of all, I welcome immigration for the reasons I said. I think it’s made our country stronger in so many ways, whether it’s economic or cultural. As a second-generation migrant myself it’s something I can very much relate to.

“But the connection you’ve made between immigration and, in this case, an issue around law enforcement, I don’t think it’s a fair connection to make.”

He continued: “What we’ve had regarding that issue of gangs that prey on young children for sexual purposes is that for many years, under successive governments, we have turned a blind eye to the obvious.

“Any normal person looking at the recent convictions of gangs that abuse children would have noticed that a vast majority are from a Pakistani heritage and we cannot ignore that. If you do ignore that, if you sit in a position of power like me and you ignore that, what you actually end up doing is fuelling the voices of extremism that are out there that will then prey on that.”

The issue of grooming gangs is a politically charged area, and one being exploited by far-right anti-Muslim activists such as Tommy Robinson, who was recently appointed as an adviser on the issue to the Ukip leader, Gerard Batten. Some academics have warned that the area is more complex than often billed.

Asked about the widely reported case of a Syrian boy in Huddersfield who was filmed being bullied, Javid said he had experienced “a very, very similar incident” when starting secondary school.

Javid said: “I was absolutely outraged, and frankly it reminded me of an incident I had myself when I was 11 at school. That was the immediate memory that came back to me. And obviously I hated it, and I thought how that young boy must feel.”

On Brexit, Javid said the long-awaited government white paper setting out a new immigration policy was “very unlikely” to be published before next week’s key vote on Theresa May’s deal.

He defended the idea that lower-paid workers will be kept out, when asked about the CBI’s stated view that this could cause significant damage to the economy.

“I’d say gently to the CBI that they don’t know what the prime minister has suggested. These are discussions going on inside government, and the last time I looked at the cabinet table I didn’t see the CBI sitting around it,” he said.

Javid added: “The broad direction is, I think, the right one, which is that we will create an immigration system that is based on skills and not on the nationality of people.

“What we’re going to do is have an immigration system that’s in our national interest, and that’s not what we’ve had up until now, We’ve had freedom of movement, which means we haven’t been in control of who enters our country – those individuals have, just because of their nationality. And that’s going to change.”