The jailed former president of the Maldives says he may not return home after being temporarily freed to seek medical treatment in Britain.

Mohamed Nasheed says he has yet to decide whether he can better serve the struggle for democracy inside his country or abroad.

Nasheed became the Indian Ocean nation's first democratically-elected president in 2008. In 2015, he was sentenced to 13 years imprisonment for ordering the arrest of a judge when he was in power in 2012.

He was released last week to so he could undergo spinal surgery. The Maldives government says he has given a guarantee to return and serve out his sentence.

Nasheed told reporters in London on Monday that "I will definitely go to the Maldives ... The question is how and when."