"If the rule of law and autonomy are threatened, Hong Kong's success as one of the world's most important worldwide financial and trading centres is at risk".
The legislation also bans the export of crowd-control munitions, including tear gas and rubber bullets to the Hong Kong police force.
Stung by the arrests of hundreds of protesters this week, the city's pro-democracy movement has spent the past few days regrouping and mobilising for local elections tomorrow which it hopes will deliver a resounding message of popular support. If he does neither, it will become law automatically.
Trump's comments come as he mulls signing congressionally approved legislation in support of the anti-Beijing activists - or bow to Beijing's threats of retaliation if the laws pass.
A spokesman for the lawmaker, a prominent critic of the Chinese government, did not immediately respond to a request for comment.
"He's got a million soldiers standing outside of Hong Kong that aren't going in only because I ask him, 'Please don't do it, you'll be making a big mistake, it's going to have a tremendous negative impact on the trade deal, ' and he wants to make a trade deal". He's a friend of mine. "He's a friend of mine, he's an incredible guy".
"They are afraid of contact with other people because they will think that maybe social workers or lawyers are going to persuade them to surrender", he said. Okay? We have to see them work it out.
The legislation authorizes sanctions on Chinese and Hong Kong officials involved in human rights abuses and requires the State Department to conduct an annual review of the special autonomous status that the USA grants Hong Kong in trade matters.
President Donald Trump, who is seeking a resolution to a tit-for-tat tariff trade war with Beijing, was vague on Friday when asked whether he would sign the bills.
"I'd like to stress once again that Hong Kong is part of China, and Hong Kong affairs are China's internal affairs. China wants it. We want it". In the past, China has reacted to perceived slights by denying permission for US Navy vessels to make port visits to Hong Kong, he noted.
Despite the measure's near-unanimous support in the House and Senate, Trump has left open the possibility of a veto to pave the way for a trade deal with China.
The bill authorizes sanctions on Chinese and Hong Kong officials involved in human rights abuses and would mandate the State Department to annually review special autonomous status that the USA grants Hong Kong on trade.
Months of increasingly violent street protests in Hong Kong have raised fears that China might send troops from the mainland to crush the unrest, but there has been no sign of the massive intervention to which Trump referred.
Cheung said the patrol of police will encourage people to feel a sense of security that police are around to protect them when they go out to cast their votes, instead of deterring any people.