China issued a stern warning to the United States on Friday, stating that it would "not tolerate interference," following the US State Department's condemnation of Hong Kong's announcement of bounties on six activists living abroad.

The US had described the move as "a form of transnational repression."

On Tuesday, Hong Kong announced rewards of HK$1 million (approximately $130,000) for information leading to the arrest of six individuals currently residing abroad, who are accused by the city's authorities of national security violations.

US State Department spokesperson Matthew Miller stated on Thursday that "the extraterritorial application of Hong Kong's national security laws is a form of transnational repression that threatens US sovereignty and the human rights and fundamental freedoms of people all over the world."

On Friday, China stressed that the extraterritorial application of the law "is entirely in line with international law and standard practices," accusing the United States of "abusing the concept of national security."

"China is strongly dissatisfied and firmly opposes [this]. Hong Kong affairs are purely China's internal affairs, and we do not tolerate interference and meddling by any external power," Foreign Ministry spokesperson Mao Ning told a regular press briefing.

"We urge the US side to earnestly respect China's sovereignty and Hong Kong's laws, and stop supporting these anti-China figures who sow chaos in Hong Kong," she said.

Hong Kong's bounty announcement this week marked the third time authorities have offered rewards of HK$1 million for assistance in capturing individuals wanted on national security charges.

Miller confirmed that some of the activists on the latest list were based in the United States.

The bounties are seen as largely symbolic given that they are for people living in nations unlikely to extradite political activists to Hong Kong or China.