RIO DE JANEIRO — Baseball and softball will return to the Olympics in Tokyo in 2020, but there is no guarantee the sports will remain beyond that year.

Four other sports — karate, skateboarding, sport climbing and surfing — will also be a part of the program in Tokyo. The International Olympic Committee formally approved the additions on Wednesday.

Beginning with the 2020 Games, each Olympic host can propose adding sports with national appeal. The I.O.C. has also been eager to attract younger audiences and hopes that sports like skateboarding and surfing will do so.

Skateboarding and sport climbing could take place in the heart of Tokyo and would not require the construction of permanent stadiums.