Japan is being urged by Hong Kong citizens to become more serious about safeguarding their freedoms and human rights as China makes moves to tighten its grip on the territory, but it has been caught in a dilemma in consideration of the mainland.

As Sino-Japanese relations have been improving by effectively shelving their territorial dispute in the East China Sea, both Asian powers have been keen to work in tandem to revitalize their economies hit hard by the outbreak of the new coronavirus.

Tokyo, however, has also emphasized its alliance with the United States, which has boosted pressure on the Communist-led Chinese government in the wake of Beijing's attempt to push a national security law for the democratic former British colony.

For the past four years, Japanese Prime Minister Shinzo Abe has built a personal rapport with U.S. President Donald Trump, who has been nagging China in an apparent bid to gain public support in the run-up to the presidential election in November.

"Given his friendship with Trump, Abe may want to demonstrate his clear commitment to joining hands with the United States to tackle the Hong Kong issue, and he might wish to act to back its citizens," a diplomatic source in Beijing said.

Pro-democracy supporters are stopped and searched by police during a rally against the national security law in a shopping mall on June 30, 2020 in Hong Kong, China. (Getty/Kyodo)

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On social media platforms, many Hong Kong and Japanese users have called on Abe to implement measures to help residents of the special administrative region, such as allowing them to immigrate to Japan, as Britain and Taiwan have considered doing so.

"But mainland China is one of the most important trading partners for Japan and vice versa. They have no option but to deepen cooperation as their economies have plunged in the aftermath of the virus pandemic," the source said.

"For the time being, Japan cannot take actions that could irritate China even if it is rapped by other democratic nations for doing nothing. Abe is certain to take a low-key approach to Hong Kong at least before the U.S. presidential election," the source added.

Abe has also been asked by conservative Japanese lawmakers to put an end to his "weak-kneed diplomacy" toward China, which has been facing international condemnation over its purported human rights abuses in Hong Kong and against ethnic minorities in Xinjiang and Tibet.

Such politicians have traditionally stressed the significance of the alliance between Japan and the United States, especially when the security environment in the Asia-Pacific region has worsened amid Beijing's military buildup in the South China Sea.

Abe's popularity has already been on a downward slope, due largely to what critics call his "initial fumbled response" to the virus spread, and scandals, including the first postwar arrest of a former justice minister for alleged vote buying.

"Core members of the Cabinet have become concerned that conservatives, a key support base for it, will raise their fists in anger," a Japanese government source in Tokyo said. Voters view Abe as being right-wing when it comes to security policy.

A man is being stopped and searched by police during a rally against the national security law in a shopping mall on June 30, 2020 in Hong Kong, China. (Getty/Kyodo)

The Abe administration has been "fretting about how it should show its strong stance against China," while pledging to work together with the United States over matters related to Beijing, the source added.

Under the mainland's "one country, two systems" policy, Hong Kong was promised it would enjoy the rights and freedoms of a semiautonomous region for 50 years following the former British colony's return to Chinese rule in 1997.

Nevertheless, China on Tuesday enacted a national security law to crack down on what Beijing sees as subversive activity in Hong Kong, a move that could jeopardize human rights and freedoms there.

After China's parliament in late May passed a resolution regarding the introduction of the security legislation for Hong Kong, the United States swiftly decided to begin revoking the special treatment extended by law to the region.

The U.S. State Department said Monday that it is terminating controlled defense exports to Hong Kong and will take steps to impose the same restrictions on the transfer of U.S. defense and dual-use technologies to the region that it applies to mainland China.

In contrast, Japanese Chief Cabinet Secretary Yoshihide Suga told reporters on Tuesday that Tokyo will continue to communicate with Beijing, although China's enactment of the security law for Hong Kong was "regrettable."

Victor Teo, a regional expert at the University of Hong Kong, said Japan "might be forced or persuaded by Washington to act in solidarity in some aspects," but it is "unlikely" that Tokyo will "swing towards the United States to confront China fully."

Strategic prudence would compel "Japan to take a moderate position and maintain cordial relations with both the United States and China," he added.

Meanwhile, Chinese President Xi Jinping's first state visit to Japan since he took power in 2013, which has been delayed owing to the virus epidemic, may not be realized against a backdrop of backlash from the public at home and the United States.

Japanese Defense Minister Taro Kono, a former foreign minister, said at a press conference in Tokyo on Tuesday that China's endeavors to change the status quo unilaterally would have a grave impact on Xi's planned trip.

Another diplomatic source familiar with ties between Tokyo and Beijing also said, "Under the current circumstances, it is almost impossible for Abe's government to invite President Xi to visit Japan in the near future."