Listhaug's comments came as she returned criticism of her visit with a family of Syrian refugees in Norway's northern Finnmark county earlier this week.
The visit, during which Listhaug accepted a Syrian family's invitation to cake at their home in the village of Mehamn, was intended to give the minister an impression of integration in the region, reports newspaper VG.
That evening she posted photos of the visit on her Facebook page – provoking critical comments from a series of social media users.
Comments including “forget trying to integrate these people,” “they only lie to heathens,” and “don't fill municipalities with people when there isn't enough work for the Norwegians living there” were among those posted.
Many of the comments focused on the hijab the mother of the Syrian family is seen to be wearing in the pictures.
“Get that hat off them so they can integrate PROPERLY,” read one comment.
“Go back to their own country and build it up. There you can have your hijab all day,” wrote another user.
“Sylvi, I support you nine times out of ten, but this is the exception,” read another comment.
The negative comments prompted Listhaug to post a series of responses as well as a long post of her own in the thread.
“I think this turned out to be an example of me having to put my foot down and be clear. I do not accept insults or threats, and nor will I ever do so. I was invited for coffee and cake at the home of a nice family of Syrian background. They were pleasant and extremely hospitable,” the minister later told VG.
The father of the Syrian family told the newspaper that he did not wish for the photos to be republished, given the number of negative comments directed at the family.
“I am very sorry [about it],” he said.
Listhaug stressed that she remains against the wearing of hijabs by children, and that she does not believe the fully face-covering burka and niqab have a place in Norwegian society.
“But a grown woman in her own home has the right to wear what she wants. It's okay to view things differently, but and we should take that into consideration, but when so many offensive comments were posted, I'd had enough,” she said to VG.
“It is fundamental in Norway that we have freedom of speech and the right to discuss important and difficult social issues. I encourage that, but, when it turns into mudslinging I draw the line. This mother does not deserve nasty comments for being nothing other than kind and welcoming. That is unfair and it is not Norwegian,” she added.
The minister also said that she did not mind being criticised by those who considered themselves her supporters.
“I receive criticism from many perspectives and I'm fine with that. Supporting strict asylum and immigration policies does not mean you have nasty and racist opinions. Most people manage to keep things civil. But when people don't do that and go over the line, I try to tell them,” she said.