China says it won't 'sit by' on Hong Kong, Trump expresses concern

China has warned that it will not "sit by and watch" the unrest unfolding in Hong Kong, as US President Donald Trump expressed concern over the risk of a violent response to pro-democracy protests.

Trump urged his Chinese counterpart Xi Jinping to meet with demonstrators, while US National Security Advisor John Bolton warned Beijing against creating a "new" Tiananmen Square in Hong Kong, referring to the deadly 1989 crackdown on protesters in Beijing.

The weeks-long Hong Kong protests were sparked by opposition to a plan to allow extraditions to the mainland, but have since morphed into a wider -- sometimes violent -- call for democratic rights.

The movement represents the greatest challenge to Beijing's authority since the city was handed back by the British in 1997 under a deal that allowed it to keep freedoms that many Hong Kongers feel are being eroded.

Images taken by AFP on Thursday showed thousands of Chinese military personnel waving red flags and parading at a sports stadium in the city of Shenzhen, just across the border from Hong Kong.

Dozens of armoured personnel carriers and supply trucks were also parked nearby.

Chinese state-run media reported this week that the elements of the People's Armed Police (PAP), which is under the command of the Central Military Commission, were assembling in Shenzhen.

China's ambassador to London, Liu Xiaoming, said on Thursday that Beijing would not "sit by and watch", warning that his government had "enough solutions and enough power to quell the unrest swiftly".

Analysts have said the potentially catastrophic economic and political consequences will deter Beijing from any overt boots-on-the ground intervention in the global financial hub.

Trump urged a peaceful solution on Thursday, telling reporters that he is "very concerned" over a possible crackdown and saying that if Xi "sat down with the protesters... I'll bet he'd work it out in 15 minutes."
Trump added, "I know it's not the kind of thing he does." The US president also said he would be speaking with Xi "soon."
In an interview with VOA News published Thursday, Bolton said that "people in America remember Tiananmen Square," warning China that "it would be a big mistake to create a new memory like that in Hong Kong."