Taiwan will provide the people of Hong Kong with “necessary assistance”, President Tsai Ing-wen said, after thousands in the Chinese ruled territory protested against Beijing's plans to impose new national security laws.

Taiwan has become a refuge for a small but growing number of pro-democracy protesters fleeing Hong Kong, which has been convulsed since last year by anti-Beijing and anti-Hong Kong government protests.

Hong Kong police fired tear gas and water cannon to disperse thousands of people who rallied on Sunday to protest against Beijing's move to introduce new national security laws.

Writing on her Facebook page late on Sunday, Tsai said the proposed legislation was a serious threat to Hong Kong's freedoms and judicial independence.

"Bullets and repression are not the way to deal with the aspirations of Hong Kong's people for freedom and democracy," she added.

“In face of the changing situation, the international community has proactively stretched out a helping hand to Hong Kong's people,” Tsai wrote.

Taiwan will “even more proactively perfect and forge ahead with relevant support work, and provide Hong Kong's people with necessary assistance”, she wrote.

Taiwan has no law on refugees that could be applied to Hong Kong protesters who seek asylum on the island. Its laws do promise, though, to help Hong Kong citizens whose safety and liberty are threatened for political reasons.

The number of Hong Kong immigrants to Taiwan jumped 150 per cent to 2,383 in the first four months of 2020 from the same period last year, official data shows.

Johnny Chiang, chairman of Taiwan's main opposition party, the Kuomintang, said Tsai's government was vocal about support for Hong Kong on the election campaign trail but had failed to provide meaningful help since Tsai was re-elected in January.

“Don't let 'supporting Hong Kong' only be a slogan of empty promises [...] Bring up your thoughts on legislation. Support Hong Kong with real actions,” Chiang said, referring to parliamentary bills to give political asylum for people from Hong Kong.

The small New Power Party also urged Tsai's cabinet to establish a special task force to give “tangible assistance” to Hong Kong people.

The Hong Kong protests have won widespread sympathy in Taiwan, and the support for the protesters by Tsai and her administration have worsened already poor ties between Taipei and Beijing.

China has accused supporters of Taiwan independence of colluding with the protesters.

China believes Tsai to be a “separatist” bent on declaring the island's formal independence. Tsai says Taiwan is already an independent country called the Republic of China, its official name.