President Donald Trump has tied a US trade deal with China to humane resolution of the weeks of protests wracking Hong Kong.
His tweets came hours after the US State Department said it was "deeply concerned" about reports of movement of Chinese paramilitary forces along the Hong Kong border and warned that continued erosion of the territory's autonomy put at risk the preferential status it enjoys under U.S. law.
Trump, in his remarks on Twitter, appeared to suggest a personal meeting with Chinese President Xi Jinping to help resolve the crisis.
"Of course China wants to make a deal. Let them work humanely with Hong Kong first!" Trump said on Twitter.
"I have ZERO doubt that if President Xi wants to quickly and humanely solve the Hong Kong problem, he can do it. Personal meeting?"
Trump, who has been seeking a major deal to correct trade imbalances with China ahead of his 2020 re-election bid, has faced mounting criticism from Congress and elsewhere for not taking a stronger public line on Hong Kong and for his characterisation of the protests earlier this month as "riots" that were a matter for China to deal with.
In his tweets on Wednesday, Trump also said that his delay in 10 per cent tariffs on more than $US150 billion in Chinese imports to December 15 from September 1 "will be reciprocated" by China and that "much good will come from the short deferral to December."
His comment appeared to contradict senior officials in his administration, who said earlier that no concessions were made by Beijing in response to the delay announced on Tuesday.
Trump's tougher stance on Hong Kong followed an internal debate within the White House and State Department over whether the United States was looking too compliant as the Chinese appeared to be preparing for a crackdown.
A source familiar with the deliberations said while an even-handed approach was smart, it was not the right signal to send in this case.