Clashes erupted once again between Hong Kong police and pro-democracy protesters - many of whom called on US President Donald Trump to help bring democracy to the Chinese-ruled city.

Man wearing "Make Hong Kong Great Again" hat (Getty)

Thousands of Hong Kong protesters chant the U.S. national anthem and call on President Donald Trump to ‘liberate’ the Chinese-ruled city. More here: https://t.co/LRX6ojJEaq pic.twitter.com/5qAzATMLd8 — Reuters Top News (@Reuters) September 8, 2019

While there have always been a handful of protesters waving US national flags in recent months, today’s march from the US consulate looks to be the most red, white and blue protest that Hong Kong has seen pic.twitter.com/a3cyl6X5St — Aaron Mc Nicholas (@aaronMCN) September 8, 2019

While the protest was largely peaceful, some activists constructed barricades, smashed windows, set objects on fire, and vandalized the MTR metro station in the Central district - home to banks, jewelry shops and high-fashion shopping arcades. They were met with a sharp response from police.

Hong Kong police are psychotic. pic.twitter.com/6RLYXOfH0o — Ian Miles Cheong (@stillgray) September 8, 2019

Crowds dispersed from the Central business district moved on to the nearby Admiralty bar district of Wan Chai, and then on to Causeway Bay in what Reuters describes as a "now familiar pattern of cat-and-mouse clashes" over the past three months of unrest.

"We can’t leave because there are riot police," said 20-year-old 'Oscar' in Causeway Bay. "They fired tear gas from the station. We are heading to North Point," located to the east.

Thousands of protesters earlier sang the Star Spangled Banner and called on U.S. President Donald Trump to “liberate” the city. They waved the Stars and Stripes and placards demanding democracy. “Fight for freedom, stand with Hong Kong,” they shouted before handing over petitions at the U.S. Consulate. “Resist Beijing, liberate Hong Kong.” -Reuters

A riot police officer fires a tear gas canister during a rally in Central, Hong Kong, China September 8, 2019. REUTERS/Kai Pfaffenbach

Hong Kong Wanchai Metro Station Now! pic.twitter.com/RyY2o6xbCG — Carl Zha (@CarlZha) September 8, 2019

On Saturday speaking from Paris, US Defense Secretary Mark Esper urged Beijing to exercise restraint over the Hong Kong protests.

President Trump last month suggested that China should "humanely" settle the Hong Kong situation before a trade deal is inked between the two countries.

China, meanwhile, has accused the United States and Britain of fomenting unrest.

Last week Hong Kong's Chief Executive Carrie Lam announced that she would meet some of the protesters' demands - chief among them fully withdrawing a controversial extradition bill which would have allowed the extradition of suspects to mainland China to stand trial in Communisty Party courts, vs. Hong Kong's independent judiciary which dates back to British rule.

Lam's olive branch hasn't worked, however, as the protests have evolved into a broad anti-government call for democracy.

Washington Responds

US lawmakers will address the Hong Kong protests as a top priority when they return to work after recess next week, according to Senate Minority leader Chuck Schumer (D-NY).

Schumer urged Senate Majority Leader Mitch McConnell, a Republican who sets the floor agenda, to bring up a bipartisan bill that would require an annual justification of the special treatment afforded by Washington to Hong Kong, including special trade and business privileges, under the U.S. Hong Kong Policy Act of 1992. The legislation, called the Hong Kong Human Rights and Democracy Act, would also mandate that officials in China and Hong Kong who have undermined the city’s autonomy are vulnerable to sanctions. -Reuters

On Sunday, protest organizer Joshua Wong - the face of the "Umbrella" movement from five years ago, was re-arrested at the airport while returning from Germany and the United States for breaching the conditions of his bail. He was previously charged with inciting and participating in an unauthorized rally outside police headquarters on June 21, and subsequently released on bail.

"Preliminary legal advice suggested that the court had acknowledged and approved my trips to Germany and the U.S. when it granted bail on Aug. 30," Wong said in a statement. "Therefore, it is believed that there are some mistakes have been made on the bail certificate."