A man who has been living in Afghanistan away from his young children for a year said he did not know when his family would be reunited.
The father, who has a British passport, said he had to remain in Afghanistan to protect his wife while the country was under Taliban rule.
Their three children came to the UK in 2021 with other relatives and lived in a hotel in Luton for a year.
The Home Office said British citizens could apply for a spouse visa.
The children, now aged nine, 11 and 13, were separated from their parents when a bomb went off at Kabul Airport in August 2021.
Thousands, particularly those who had connections to US and British forces, had gone there to try to fly out of the country in the wake of the US withdrawal, when the Taliban regained control of the capital.
The family had gone to the airport together and were then split up in the ensuing chaos, but the children managed to find other family members and travelled with them to the UK that month, leaving their parents behind.
The father, who already had a British passport and had lived in Britain previously, is not being identified by the BBC for safety reasons.
He said he would have considered taking his children back to Afghanistan to keep the family together but he thought their education in the UK was more important.
"The school is abandoned in Afghanistan," he said.
"I cannot take my kids back to Afghanistan, this is the reason - because of their education."
In order for the father to get a UK visa for his wife, he said he had been told he would need a confirmed job offer in the UK, or proof of earnings, which he said would not be possible to obtain from Afghanistan.
"I don't have the requirements at the moment because I would have to stay and work and get six months' pay slips and I can't stay here for six months because of my wife," he said.
"She cannot go shopping to buy food [without a male escort] because of the situation in Afghanistan, especially for women - they're asking where you are going, who you are."
He said his wife's situation had led to conflicting thoughts about what to do with their children.
"My wife is crying every day for the children. I might have to take my kids back to Afghanistan for her mental well-being," he said.
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After staying in a hotel in Luton for a year, the children and their relatives recently moved into a house in the Midlands.
Their eldest daughter, aged 13, said her father had managed to visit her and her brother and sister, "for a few weeks", but he had then returned to their mother.
The teenager said she was unable to communicate with parents who "don't have any internet".
"That is hard for me," she said.
A spokesman for the Home Office said it did not routinely comment on individual cases but said the government was "committed to providing protection for vulnerable and at-risk people fleeing Afghanistan".
"The situation is complex and presents significant challenges, including securing safe passage out of the country for those who want to leave - and who are eligible for resettlement in the UK," the Home Office said.