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.

“This time I came (to Japan) to draw attention to the amendments bill,” Chow said in fluent Japanese during the news conference at the Japan National Press Club on Monday.

“I want the Japanese government to pay more attention to this dangerous bill and put up guards (against it),” she said.

The extradition bill would allow the Hong Kong government to extradite certain criminals to mainland China, although the special administrative city government has claimed political prisoners would not be handed over to Beijing.

Chow pointed out that the extradition bill could be applied to foreign residents and visitors to Hong Kong as well, claiming that it would severely compromise freedom in Hong Kong and also damage its status as an international financial center.

Unlike other Chinese cities, Hong Kong is allowed to maintain a high level of autonomy under Beijing’s “one country, two systems” policy until at least 2047.

But the city’s political autonomy has been considerably compromised in recent years under the growing influence of the mainland’s central government.

During a regular news conference on Monday, Chief Cabinet Secretary Yoshihide Suga said the Japanese government is “paying close attention” to the extradition bill, and it hopes the one country, two systems policy will stay in place and that Hong Kong maintains its “free and open social system.” But he didn’t elaborate further.

On May 16, U.S. Secretary of State Mike Pompeo met with Hong Kong pro-democracy leader Martin Lee in Washington and expressed concerns about the bill, which the State Department says threatens Hong Kong’s rule of law.

The organizer of Sunday’s protest march claimed 1.03 million people joined the demonstration, while the Hong Kong government put its estimated number at 240,000. The population of the city is about 7.48 million.