Tokyo should put pressure on the Hong Kong government to withdraw a controversial bill that would allow extraditions to mainland China, given Japan's strong economic ties with the former British territory and the large number of mutual visits by tourists, a high-profile pro-democracy activist told a news conference in Tokyo.

Agnes Chow, a 22-year-old member of Demosisto, a Hong Kong party calling for the democratic self-determination of Hong Kongers, arrived in Tokyo on Monday after participating in Sunday's massive protest march against the bill in the semi-autonomous region.

Chow, a college student with an affinity for Japanese pop culture, served in 2014 as a spokesperson of a student organization that participated in the Umbrella Movement in Hong Kong.