Hong Kong does not have an extradition agreement with Taiwan. Its government cited Ms. Poon’s killing, and the obstacles to sending Mr. Chan to Taiwan, when it introduced legislation in February that would have allowed Hong Kong to send criminal suspects to places with which it does not have extradition treaties.
That set off huge protests because one such place is mainland China, where the murky judicial system is under the control of the Communist Party.
Hong Kong’s chief executive, Carrie Lam, said last month that she would withdraw the bill, but protests have continued over other issues, including demands to expand direct elections and to investigate the police’s use of force against demonstrators.
A march is planned in the Kowloon area of Hong Kong on Sunday to press for those demands, although the police have officially objected to it. Protesters also plan to call for a reorganization of the police force and an end to the ban on masks that Mrs. Lam recently enacted, using emergency powers, in an effort to tamp down the demonstrations.
In its statement Thursday, Taiwan said it would provide evidence in Mr. Chan’s case on a “foundation of equal status, dignity and mutual benefit.” Taiwan had previously said it would not agree to Mr. Chan’s extradition under the contentious legislation, on the grounds that the bill would have treated the self-governed island as a part of China.