Kadiza Sultana (left), Shamima Begum (center), and Amira Abase going through security at Gatwick airport before catching their flight to Turkey. (Photo: AP)

The Bangladeshi government has rejected a demand from the British government that Shamima Begum, who ran away from home in the UK aged 15 to join Islamic State, known as IS, in Syria, go there rather than be taken back by the UK.

Now aged 19, Begum recently gave birth to a baby and has said she wants to return to the UK.

But Home Secretary Sajid Javid wants to remove her citizenship, and had suggested she go to Bangladesh instead, believing her to qualify as a Bangladeshi citizen through her mother.

This proposal has provoked a stern response from the country's foreign minister Shahriar Alam.

"She is a British citizen by birth and never applied for dual nationality with Bangladesh," he said. "There is no question of her being allowed to enter into Bangladesh.

Speaking to the BBC at a refugee camp in Syria, Begum also dismissed the idea.

"I wasn't born in Bangladesh, I've never seen Bangladesh and I don't even speak Bengali properly, so how can they claim I have Bangladeshi citizenship," she said.

According to the terms of the 1981 British Nationality Act, if the home secretary is satisfied it would be "conducive to the public good" and they would not, as a result, become stateless, it is possible for a person to have their citizenship taken away.

Javid said he would not leave an individual stateless and has said Begum's son - whose father is Dutch - may be granted British citizenship.

"Children should not suffer. So, if a parent does lose their British citizenship, it does not affect the rights of their child," he told the House of Commons.

Begum and school friends Kadiza Sultana, who has since died, and Amira Abase, whose fate is unknown, ran away four years ago at the age of 15, but Begum told the BBC that she had hoped "Britain would understand I made a mistake, a very big mistake, because I was young and naive."

Her husband, an Islamic convert, was an armed jihadi who is believed to have surrendered to Syrian forces in the last few weeks, was imprisoned and tortured by IS, which is what Begum says made her change her mind about the group and the cause.

Begum says she has had two other children who have died because of sickness and does not want the same fate to befall her third, hence wanting to return to the UK.

When asked in a recent interview about how she felt about IS beheadings and executions, Begum said "I knew about those things and I was okay with it…. from what I heard, Islamically that is all allowed. So I was okay with it."

She also added "When I went to Syria, I was just a housewife for the entire four years - stayed at home, took care of my husband, took care of my kids ... I never did anything dangerous. I never made propaganda. I never encouraged people to come to Syria."