Lam said in a press conference that the US legislation would have an impact on the city's economic development by undermining confidence and creating an unstable environment for Hong Kong-based businesses, reports Efe news.
"This is completely unnecessary and very regrettable," Lam said. "For now, it undermines confidence; it creates an unstable environment."
The leader of the Chinese semi-autonomous region added that US firms were also concerned, as they too might be affected by the law.
"All this is creating uncertainty and won't go well for any economic development," Lam said.
She described the HKHRDA as clear interference by Washington in Hong Kong's internal affairs, echoing the stance of Beijing, which on Monday responded by banning the stopover of US military ships and aircraft in the city and imposed sanctions on several non-governmental organizations and human rights groups.
"We will follow the law in supporting the central government and we will follow up on the measures they take," said Lam.
The Chief Executive also criticized the American law for suggesting that the rights of Hong Kong residents were being violated and stressed that they enjoyed freedom of the press, religious liberty and freedom of assembly.
The HKHRDA, which was signed into law by US President Donald Trump, requires the State Department to conduct reviews at least annually evaluating whether Hong Kong retains enough autonomy to merit a change to its current status as a preferential trade partner. It also prescribes sanctions on individuals found to have abused human rights in Hong Kong, including Chinese officials.
"The US government will have to conduct certain reviews after this passing; let's see how they conduct them," she said. "Of course, there will be an impact. This is an overseas foreign government taking such a measure."
On the other hand, Lam announced a fourth round of relief measures to bolster the economy of the region, whose gross domestic product could contract by up to 1.3 per cent for the entire fiscal year as it reels from the double impact of both the ongoing US-China trade war and the massive anti-government protests that have swept the city since June.
Lam did not specify what the new measures would look like. Instead, she committed to finding a way of stopping the violence as soon as possible to allow the economy to recover.
"But now, cold water has been poured on the situation," she said, in reference to the US law.
Retail sales sank by 24.3 per cent in October due to the protests. Hong Kong's finance secretary, Paul Chan, said it was the biggest inter-annual drop in the city's history.
( With inputs from IANS )