Five additional sports, including skateboarding and surfing, have been recommended by the organizers of the Tokyo Olympics for inclusion at the 2020 Summer Games, it was announced on Monday.

Baseball/softball, karate and climbing were also given the thumbs up under a proposal that will see a total of 18 new medal events, nine each for men and women, contested by an extra 474 athletes at the games.

"This package of events represents both traditional and emerging, youth-focused events, all of which are popular both in Japan and internationally," Tokyo organizers said in a statement.