The US consulate in Hong Kong on Friday said it was "ludicrous" to suggest its diplomats meeting with pro-democracy politicians could breach the city's new national security law, a charge levelled in a recent Chinese state media report.
Earlier this week, China's state-owned tabloid Global Times ran a story suggesting a recent meeting between US Consul General Hanscom Smith and a pro-democracy politician could violate the new legislation.
Beijing imposed a sweeping national security law on Hong Kong at the end of June targeting subversion, secession, terrorism and colluding with foreign forces.
In a statement on Friday the US consulate said its diplomats met with a variety of political figures including pro-establishment politicians and the pro-democracy opposition.
"These meetings are neither secretive nor mysterious," the consulate said.
"The suggestion that those who meet with consulate representatives are engaging in 'collusion' is ludicrous," it added.
The security law was a direct response by Beijing to months of huge and often violent pro-democracy protests that erupted in Hong Kong last year.
Millions took to the streets calling for police accountability and the right to elect Hong Kong's leaders.
Beijing dismissed the movement, portraying it as a plot by foreign forces to undermine China.
The broadly worded security law includes bans on people lobbying or supporting foreign sanctions or inciting hatred of China.
It has sent a political chill through Hong Kong, a semi-autonomous city supposedly guaranteed certain freedoms not seen on the Chinese mainland as well as autonomy for 50 years after the city's 1997 handover from Britain.
In its statement, the US consulate called the law "draconian" and said its imposition was "never about security".
"Instead, it was intended to silence democracy advocates and threaten those who engage in even the most routine forms of free speech," it said.
"It would be an enormous tragedy if it crushed the very openness, diversity, and vitality that are at the heart of what makes Hong Kong so unique."