Hong Kong (CNN) United States President Donald Trump has suggested that China should deal with protests in Hong Kong "humanely" before making a trade deal with the US.

In a series of tweets late Wednesday, Trump praised Chinese President Xi Jinping as a "good man" and suggested the two leaders hold a personal meeting to sort out the political crisis in Hong Kong and the escalating trade war between the US and China.

"Of course China wants to make a deal. Let them work humanely with Hong Kong first!" Trump tweeted.

On Tuesday, the US announced that it would postpone new tariffs on some Chinese-made consumer goods until December, instead of applying them in September as originally planned.

Meanwhile, increasingly violent and unpredictable anti-government protests have wracked Hong Kong. The unrest, which began in early June, risks becoming the most serious challenge to Xi since he came to power in 2012.

Trump, who has faced criticism for not taking a tough enough stance on China over Hong Kong, said that he believes Xi can solve the situation "quickly and humanely."

"I know President Xi of China very well. He is a great leader who very much has the respect of his people. He is also a good man in a "tough business,"' Trump said.

"I have ZERO doubt that if President Xi wants to quickly and humanely solve the Hong Kong problem, he can do it. Personal meeting?"

I know President Xi of China very well. He is a great leader who very much has the respect of his people. He is also a good man in a "tough business." I have ZERO doubt that if President Xi wants to quickly and humanely solve the Hong Kong problem, he can do it. Personal meeting? — Donald J. Trump (@realDonaldTrump) August 14, 2019

Fears that Chinese forces could enter the city and quash the protests have been rife in Hong Kong, where memories of the 1989 Tiananmen Square massacre -- where Peoples' Liberation Army troops brutally put down pro-democracy protests -- is still fresh in residents' minds.

Trump's tweets come as China has deployed large numbers of paramilitary personnel close to the Hong Kong border, in what observers say is intended to send a message to protesters in the Asian financial hub

On Wednesday, CNN teams on the ground in the mainland Chinese city of Shenzhen saw uniformed members of the People's Armed Police Force (PAP) with riot shields and batons, as well as numerous semi-militarized vehicles, stationed at the city's Bay Sports Center.

The PAP is the 1.5 million-member paramilitary force the government regularly deploys to quell protests within its borders. It is under the command of China's central military commission, headed by Chinese President Xi Jinping.

Satellite imagery shows Chinese military vehicles congregating near Hong Kong border.

But there has been no indication that the PAP are set to do that, and such an intervention could have devastating effects on the territory's economy. Analysts and US officials say it is unlikely that China would intervene militarily.

US national security adviser John Bolton warned China to "look very carefully at the steps they take" because America still remembers the Tiananmen crackdown and it would be a "big mistake to create a new memory like that in Hong Kong."

But the Chinese government has ramped up its rhetoric against protesters, with Yang Guang, a spokesman for the Hong Kong and Macao Affairs Office, China's top body in charge of affairs in the city, saying on Monday the protests showed "signs of terrorism."

Chinese officials have also accused Washington and other foreign governments of "meddling" in the protests and using them as a vehicle to attack China

Protesters are calling for greater democratic freedoms, an independent inquiry into police misconduct and the formal withdrawal of an extradition bill to the mainland.

As Beijing works out what to do with Hong Kong, it is fighting a bitter trade war with the US, a slowing economy and its standoff with the United States.