President Donald Trump boards Air Force One in Andrews Air Force Base, Maryland, en route to a rally at Mohegan Sun Arena at Casey Plaza in Wilkes Barre, Pennsylvania. (Image: PTI/AP)

US President Donald Trump addressed China over its handling of the Hong Kong protests and urged the Beijing government to protect the island's "democratic way of life".

"The world fully expects that the Chinese government will honour its binding treaty... (and) protect Hong Kong's freedom and legal system and democratic ways of life," he added.

Speaking at the UN General Assembly (UNGA) on September 24, Trump said the USA was "carefully monitoring" the pro-democracy protests. This is the gravest political crisis in the Asian financial hub since its handover from Britain to China in 1997.

"How China chooses to handle the situation will say a great deal about its role in the world and the future," he added.

This is Trump's third appearance at the diplomatic forum in New York and marked his most strident speeches on the crisis since the anti-government movement broke out in Hong Kong in March this year.

Till UNGA, Trump had largely left it to the State Department to demand respect for the handover treaty which grants the territory a "high degree of autonomy," its own judicial, legislative and executive system, and the protection of its "way of life."

Trump also fired a shot across China's bow on international trade, declaring that the time of Beijing's "abuses of the system was over".

"For years, these (trade) abuses were tolerated, ignored or even encouraged," he said, arguing that "globalism" had caused world leaders to ignore their own national interests.

Touting what he argued were the benefits of his tariff war with China, Trump reiterated his hope that a trade agreement "beneficial to both countries" could be struck.

"But as I said very clearly, I will not accept a bad deal for the American people," he said.

(With inputs from PTI/AFP)