TAIPEI (Kyodo) -- Taiwanese officials of the island's representative office in Hong Kong were forced to return home Sunday after the city government demanded that they sign a document recognizing Beijing's "one China" principle, the island's top agency handling relations with China said.

The Mainland Affairs Council said that the Taiwanese personnel at the Taipei Economic and Cultural Office in Hong Kong, operated by the council, were forced to leave the city due to "unreasonable political obstacles" the Hong Kong government had set up, adding the council issued "a stern warning and condemnation" to the government.

Taiwan's Central News Agency quoted an anonymous source as saying that seven of the office's eight staff will see their visas expire soon. To have their visas renewed, it was demanded that the staff sign the document or leave the city before Monday.

The council also said the Hong Kong government had begun to make political demands of the representative office since 2018 and the new head of the office, Lu Chang-shui, had not been able to assume his post though he was appointed that year.

The departure of the Taiwanese staff in Hong Kong came after the Macau government announced on Wednesday that it would suspend operations of its representative office in Taiwan.

Macau followed in Hong Kong's footsteps in suspending its representative office in Taiwan on May 18.

Taiwan and mainland China have been governed separately since they split amid civil war in 1949. Beijing has since regarded Taiwan as a renegade province awaiting reunification, by force if necessary.