Minors under the age of 18 will be able to apply for a visa to come to the UK under the sponsorship scheme if they have parental consent.
The new policy will initially apply to more than a thousand unaccompanied minors who have already applied under the scheme but who have been unable to travel unless they are with, or joining, a parent or guardian.
The change in position was set out in a written statement by Communities Secretary Michael Gove on Wednesday.
He said: “This policy will initially apply to the 1,000 children who have already applied to the Home Office but are unable to travel as they are not travelling or reuniting with a parent or guardian.
“After working closely with the Ukrainian government, the changes will enable a child to apply for a visa if they have proof of parental consent.”
Parental consent must be certified by an authority approved by the Ukrainian government, which includes Ukrainian consulates abroad.
The changes come after it was revealed that a teenage girl who fled Ukraine had been forced to return to the war torn country because the UK had not granted her visa request.
In a letter to the Home Secretary, the Hampstead and Kilburn MP said the older sister was given permission to travel to the UK on April 13 after a family in north London agreed to sponsor the pair.
But Ms Siddiq said the younger teenager did not have her visa application accepted by the Home Office because she was not travelling with her parents who had stayed behind to fight.
The delay in processing the visas left both teenagers stuck in a temporary hostel in Montenegro earlier this year, Ms Siddiq added.
She explained the pair were split up when the older sister came to London and the younger girl’s mother was forced to come and get her before then returning to Ukraine.