US politicians who passed the Hong Kong-related bill in the Congress do not clearly understand Hong Kong, an expert on China-US relations and a long-time Hong Kong resident said on Thursday, criticizing the passage of the bill as a move to "cover up domestic issues" in the United States.

"I do not think they really know what is going on in Hong Kong," said Fred Teng, the president of New York-based America China Public Affairs Institute, a nonprofit organization, who has lived in Hong Kong for around a decade.

The US House of Representatives passed the Hong Kong Human Rights and Democracy Act of 2019 on Tuesday, a move condemned by China.

A spokesperson for the Hong Kong and Macao Affairs Office of China's State Council described the bill as a gross intervention in China's internal affairs and a blatant backing for the Hong Kong opposition and violent radicals, according to Xinhua.

"This is not a serious bill," Teng said, calling it a "kind of bill a city council or state assembly pass - not the US Congress."

Teng also criticized US Senator Ted Cruz who visited Hong Kong recently and was vocal in supporting protests, saying his action is "just creating drama".

These are moves that "criticize other countries to cover up the domestic shortcomings," Teng said, referring to issues such as the mounting national debt, crumbling infrastructure, and significant gaps between the rich and the poor.

"Criticizing other people may make some people feel good, but it really does not solve the problem of the US domestically," he said.

Teng, who has traveled to the city more than 10 times this year alone, called for stability and safety in Hong Kong, which he said, is "a basis for democracy or freedom".

Even if people have made their voice heard and the government has not responded immediately, this is no excuse to create violence in the city, Teng said.

The four-month-long demonstrations, whose target was the extradition amendment bill, continued even after the bill was withdrawn in early September.

Hong Kong's Chief Executive Carrie Lam said last month the protesters' discontent extended far beyond the extradition bill, which included some deep-rooted problems.

"Hong Kong has always seen demonstrations. They are normal for a city," Teng said, adding that "no action the Hong Kong government has done can justify" the violent actions of demonstrators, their activities in government and public facilities and their usage of certain tools and weapons against police.

"Such actions will not be tolerated in any country or city," he said.

Teng paid tribute to the Hong Kong police while receiving an award from the Tri-State Law Enforcement Foundation Inc, a nonprofit organization that works closely with the law enforcement officials in New York, New Jersey and Connecticut, on October 17.

Teng said the Hong Kong police have, for decades, dedicated themselves to maintaining law and order in Hong Kong. He also said that a stable society is essential for democracy and freedom.

He said the police are "absolutely professional" and "very restrained" even while being "outnumbered" by demonstrators.

He said the demonstrators "are not trying to create a better Hong Kong, nor are they trying to improve Hong Kong", echoing the point made by Singapore's Prime Minister Lee Hsien Loong on Wednesday during an interview when he said the demonstrations are "intended to humiliate and bring down the government".

"I think some of them are anarchists" intending to "tear down the government," said Teng, who was formerly the chairman of both the Hong Kong Association of New York and the National US Hong Kong Business Association.

During an annual policy speech on Wednesday, Lam warned of economic challenges Hong Kong was facing and acknowledged the economy entered recession in the third quarter, according to Bloomberg.

The International Monetary Fund this week revised down its growth forecast for the city, estimating a 0.3 percent expansion in 2019, a sharp decrease from the 2.7 percent it had witnessed in April.

Teng said he was optimistic about Hong Kong's resilience, and that it would continue to get support from the Chinese mainland, which has backed Hong Kong in fields like tourism and investments.

"Since 1997, China has abided by the 'one country, two systems' all the way," he said, stressing that the central government wants the system to work and has always been letting the Hong Kong regional government officials make their decisions.

"They have not interfered in this matter, they have not interfered in all the previous matters," said Teng. "They let Hong Kong be Hong Kong."