Game of Thrones - the record-breaking fantasy drama TV series - will end after its eighth season, American broadcaster HBO has confirmed.

HBO programming chief Casey Bloys made the announcement at the Television Critics Association's conference.

The seventh season - made up of seven episodes instead of the usual 10 - is expected in summer next year, while the final season will be in 2018.

Game of Thrones is based on novels written by George R R Martin.

Now the programme has outgrown the novels, meaning producers are telling a story no-one has read.

Spin-off 'possible'

Speaking on Saturday in Beverly Hills, California, Mr Bloys said the number of episodes for the final season was yet to be determined.

"We'll take as many as the (producers) will give us," he said.

Mr Bloys did not rule out a spin-off, saying that "we're open to it, (the producers) aren't opposed to it, but there's no concrete plans right now".

Last year, Game of Thrones won a record 12 Emmy Awards for a series in a single year.

The series has picked up 23 nominations - another record - ahead of this year's annual ceremony to be held in September.