Prime Minister Shinzo Abe expressed on Wednesday his "deep concern" over unrest in Hong Kong, and called for its peaceful resolution, in a meeting with Chinese Vice President Wang Qishan.

Amid violent demonstrations in the territory, originally sparked by a controversial bill to facilitate extraditions from Hong Kong to mainland China, Abe stressed the importance of the current "one country, two systems" arrangement and added that restraint and dialogue are needed, according to Japan's Foreign Ministry said.

Abe also asked Wang, who is known to be close to President Xi Jinping, to handle the case of a Japanese professor in his 40s — detained in China on suspicion of violating Chinese law — in "a positive manner," effectively calling for his release.