Ireland captain Rory Best has announced that he will retire following this year's Rugby World Cup in Japan.

The Ulster star's contract expires after the tournament and he will take the opportunity to call time on his rugby union career on the biggest stage.

Best has played 116 times to date for Ireland, winning the Six Nations on four occasions - including two Grand Slams, one of which came as skipper.

The 36-year-old, who has made 219 appearances for Ulster, was also part of the British and Irish Lions tours to Australia and New Zealand in 2013 and 2017 respectively.

He says he now intends to bow out at "the right time", playing "at the top of my game".

"It is with mixed feelings that I announce my retirement from Ulster Rugby as of the end of this season," Best said in a statement on the Ulster website.

"This feels like the right time for me to go out on my terms, a luxury for which I feel very privileged.

"I am very excited for the end of the season with Ulster Rugby and for the upcoming World Cup with Ireland, both of which I hope to finish with a massive high, playing at the top of my game.

"In my 15 years at this brilliant club, I have been lucky to have met, played alongside, been coached by and supported by many great people.

"I would like to thank every individual for the time they have invested in me since 2004.

"I grew up supporting Ulster Rugby, have been fortunate to play and captain Ulster Rugby, and now look forward to supporting Ulster Rugby in the future with my family."