Denmark will next year declassify "being transgender" as a mental illness, lawmakers from the parliament health committee decided on Tuesday.

"It is completely inappropriate to call it a sickness," the committee's deputy chairman Flemming Moller Mortensen told AFP.

"There is a longstanding wish from the trans community in Denmark to have it removed" from the health ministry's clinical guidelines on illnesses, he added.

The move, which would come into force on January 1, is also intended to put pressure on the World Health Organization (WHO), which has yet to remove transsexualism from its list of mental disorders.

Denmark has "no more patience" with the WHO, which will discuss the issue later this year, Mortensen said.

Amnesty International hailed the Danish decision, saying it made Denmark "a role model for transgendered people's rights".

"Amnesty would also like to commend the government for its effort in the WHO, where it has worked to have the disease classification system changed," the group's Denmark chief Trine Christensen said in a statement.

Rights group LGBT Denmark also welcomed the move.

"To remove transgender from the section of mental disorders means removing an institutionalised stigmatisation of trans people," spokeswoman Linda Thor Pedersen said.