Updated at 7:33 p.m. Aug. 14.
VOA's Cindy Saine contributed to this report.
The United States says it is "deeply concerned" by reports of Chinese paramilitary movement along the border with Hong Kong, the Chinese territory that has seen 10 consecutive weeks of pro-democracy demonstrations.
"We encourage China and all parties in Hong Kong to pursue a solution that respects the liberty of Hongkongers and Hong Kong’s high degree of autonomy, as enshrined in the Sino-British Joint Declaration," a State Department spokesperson said. "It is important for the Hong Kong government to respect the freedoms of speech and peaceful assembly, as enshrined in the Sino-British Joint Declaration, and for China to respect Hong Kong’s high degree of autonomy."
On Wednesday, White House national security adviser John Bolton warned China to show restraint in its handling of the protests in Hong Kong.
"Something like 60% of the investment in mainland China goes through Hong Kong. Why? Because it has a judicial system that's trustworthy, based on the English model that we know in this country. The courts are thought to be impartial," Bolton told VOA Contributor Greta Van Susteren. "If Hong Kong loses that reputation because of a bad decision by the Chinese government, they'll have significant economic consequences in China this time, and I can tell you from what I've heard, just in the past few weeks, the mood in Congress is very volatile at this point, and a misstep by the Chinese government, I think, would cause an explosion on Capitol Hill."
He said China needs to learn from its past. "The Chinese have to look very carefully at the steps they take, because people in America remember Tiananmen Square," Bolton said. "They remember the picture of the man standing in front of the line of tanks, they remember the statue of Lady Liberty, they remember voices of the Chinese people asking for freedom and democracy, and they remember the repression of the Chinese government in 1989. It would be a big mistake to create a new memory like that in Hong Kong."
As protests have escalated in recent days, China's state-run media have showed videos of security forces gathering across the border in mainland China.
U.S. President Donald Trump said Tuesday on Twitter, "Our Intelligence has informed us that the Chinese Government is moving troops to the Border with Hong Kong. Everyone should be calm and safe!"
In comments to reporters Tuesday, Trump, who last week took a hands-off stance on the protests, said the Hong Kong situation "is a very tough situation, very tough. We'll see what happens, but I'm sure it will work out." He expressed the hope that no one would get hurt and "for liberty."
There have been fierce clashes between demonstrators and police on Hong Kong's streets. Violence also erupted at the international airport late Tuesday as riot police clashed with pro-democracy demonstrators who had taken over the airport for two straight days.
"We condemn violence and urge all sides to exercise restraint, but remain staunch in our support for freedom of expression and freedom of peaceful assembly in Hong Kong," the State Department spokesperson said.
Hong Kong residents have been protesting over their perceived erosion of freedom and lack of autonomy under Chinese control of the territory. The protests present the biggest challenge to Chinese rule of the semi-autonomous territory since its 1997 handover from Britain.