The Environment Ministry will double the number of rangers operating the nation's 33 national parks to around 200 by fiscal 2020 as part of government efforts to attract more foreign visitors to nature tourism, a source close to the matter said Monday.

The ministry is aiming to more than double the number of foreign nationals visiting national parks to 10 million in 2020, as Japan seeks to increase the number of foreign visitors to 40 million in that year when Tokyo hosts the Olympic and Paralympic Games.

The number of overseas tourists hit a record 24.04 million in 2016.

By hiring more rangers, the ministry hopes to improve its nature tourism programs, such as moss-viewing tours at Akan National Park in Hokkaido, and upgrade cycling courses in Aso-Kuju National Park in Kumamoto and Oita prefectures.

Around 100 rangers currently work at 33 national parks or nearby offices in Japan in roles including the protection of rare species and operating visitor centers.

The Environment Ministry plans to increase the number of rangers by 25 in fiscal 2017 starting in April.