As political unrest in Hong Kong has continued unabated and China has shown no sign of acceding to protesters’ demands, the administration of Prime Minister Shinzo Abe is facing mounting pressure to rescind its invitation to President Xi Jinping for a state visit next spring.

U.S. President Donald Trump’s approval this week of a bill in support of Hong Kong’s pro-democracy protesters was the latest move that could ultimately put the heat on Tokyo over its warming ties with Beijing. A Japanese government source said Abe, who has tried to build a personal rapport with Trump, could struggle to obtain U.S. understanding about Xi’s state visit here at a time when Washington and Beijing are also divided over trade and security issues.

“Relations between Japan and China have been certainly improving, but they are still fragile,” the source said, adding, “Possible U.S. involvement in Hong Kong would further complicate Japan’s stance on how to get along with China.”

“If mainland China takes radical actions to clamp down on protests in Hong Kong, the (Japanese) government might be compelled to suspend President Xi’s planned visit to Japan,” the source said.

Chief Cabinet Secretary Yoshihide Suga said at a news conference Thursday in Tokyo that he does not expect that the U.S. enactment of the Hong Kong human rights law will affect Xi’s visit.

On Wednesday, Trump signed the Hong Kong Human Rights and Democracy Act, further worsening ties between the governments of the world’s top two economies. Washington and Beijing have been engaged in a prolonged tit-for-tat trade war.

The new law directs the U.S. State Department to conduct an annual review to certify whether Hong Kong is sufficiently autonomous to justify special treatment for bilateral agreements and programs.

A 1992 U.S. law gives Hong Kong a special status separate from the rest of mainland China with regard to tariffs and visa restrictions.

The newly enacted law includes a policy of coordination with allies such as Japan and South Korea “to promote democracy and human rights in Hong Kong.”

Trump said he signed the bill “in the hope that leaders and representatives of China and Hong Kong will be able to amicably settle their differences, leading to long-term peace and prosperity for all.” Beijing has reacted harshly against his move.

Sino-Japanese ties, meanwhile, have often been strained over wartime history and territorial rows, but the two neighbors now describe their relations as having “returned to a normal track” and they have encouraged reciprocal visits by their leaders.

Beijing has been eager to deepen economic cooperation with Japan, given that the world’s second-largest economy has been slowing against a backdrop of the trade war with the United States, pundits say.

Japanese government sources said Thursday the government is making arrangements for a mid-December visit to China by Defense Minister Taro Kono to meet with his Chinese counterpart, Gen. Wei Fenghe.

If realized, it will be the first visit for a Japanese defense chief to China since March 2009, reflecting markedly improved bilateral relations.

Tokyo expects Kono’s visit to Beijing will lay the groundwork for Abe’s trip to China, which is scheduled to take place before the end of the year.

Kono plans to express Japan’s concerns over Chinese military activities in the East and South China seas, the sources said.

He is also expected to urge China to seek a peaceful solution to the unrest in Hong Kong.

Victor Teo, an expert on East Asian affairs at the University of Hong Kong, said, “Having good and strong relations with China and the United States simultaneously is the best thing Japan can hope for.”

Reflecting a thaw in ties between the two countries, China in mid-November freed a detained Japanese scholar who it claimed was spying during his visit to the nation in September.

On Nov. 15, Foreign Minister Toshimitsu Motegi told reporters that the detention of the professor at Hokkaido University was one of the matters of bilateral concern that Japan wanted to resolve to create a “good environment” to receive Xi.

But some Japanese lawmakers — including members of Abe’s ruling Liberal Democratic Party — have brazenly started to cast doubt on whether the government should facilitate Xi’s visit as a state guest.

Earlier this month, a conservative group of the LDP called on Abe’s office not to invite Xi to Japan, saying in a statement, “We cannot say that Japan-China relations have been on a normal track.”

Especially after pro-democracy parties scored a landslide victory in Sunday’s district council elections in Hong Kong, criticism against China’s Communist Party has grown across the globe, making it “more difficult for Japan to welcome Xi,” the source said.

Masahisa Sato, an LDP lawmaker who served as senior vice foreign minister under the Abe administration for around two years until September, has said in a Twitter post, “Can we welcome (Xi) as a guest of the emperor?”

Toru Kurata, a professor of Chinese politics at Rikkyo University in Tokyo, said, “As President Xi has maintained a hard-line approach toward Hong Kong, more Japanese citizens may have questions about whether Japan will invite him as a state guest.”