The People’s Liberation Army is a pillar for stability in Hong Kong and will always abide by the law, Beijing said on Friday amid concerns it might mobilise troops to help bring an end to weeks of unrest in the city.

“I want to say that the PLA in Hong Kong has always strictly abided by the Basic Law and the Garrison Law since the [1997] handover, and has faithfully carried out their defence duties,” China’s foreign ministry spokeswoman Hua Chunying told a press conference in Beijing, referring to the Hong Kong’s mini-constitution.

“The PLA in Hong Kong has been a pillar for the city’s long-term prosperity and stability,” she said, adding that Beijing would continue to support stability in Hong Kong but would not allow foreign forces to interfere in its affairs.

On Wednesday, Chinese defence ministry spokesman Wu Qian said that the protesters’ recent actions and vandalism of the central government’s liaison office in Hong Kong had challenged Beijing’s baseline.

He also said that the PLA’s role in Hong Kong was clearly stipulated by law.

On Thursday, a US State Department spokeswoman said Washington had “note[d] with concern the Chinese government’s statements”.

“We urge Beijing to adhere to its commitments in the Sino-British Joint Declaration and Basic Law to allow Hong Kong to exercise a high degree of autonomy,” she said, referring to the binding documents that stipulate the city’s administrative autonomy under the “one country, two systems” framework.

US Secretary of State Mike Pompeo also urged China to “do the right thing” in dealing with protests in Hong Kong and called on all sides to refrain from using violence.

“The president, I think, captured it right when he said that we need China to do the right thing,” he said in an interview with Bloomberg Television on Thursday, referring to US President Donald Trump.

“We hope that they’ll do that, we hope that the protests will remain peaceful.”

China and the US have traded barbs over Hong Kong in recent weeks.

Earlier this week, Hua accused the US of being the “black hand” behind the disruption in the city, which the US State Department brushed off as a “false charge”, saying the protesters’ concerns about the erosion of Hong Kong’s autonomy were “legitimate”.

Though analysts say the prospect of military intervention is extremely unlikely because of the high political cost, Wu’s remarks fuelled concern among the Hong Kong public that the PLA’s hitherto dormant presence in the city could change.

Hong Kong’s next demonstrations are set to take place on Saturday in Yuen Long – where a gang of thugs launched a vicious attack on members of the public at the town’s subway station on Sunday – and the following day in the city’s western district.

Local police refused permission for the Yuen Long protest, but organisers said it would go ahead nonetheless.

Meanwhile, the Civil Human Rights Front – which has organised earlier protests but is not directly involved in this weekend’s events – has called on foreign consulates to issue travel warnings for the city in light of the violence in Yuen Long and to press the government for greater protection for foreign nationals living in the city.

Hua likened the group’s call to “inviting the wolf into your home”.

“I think everyone can see clearly the real nature of such behaviour. It is to instigate foreign forces to interfere in Hong Kong’s affairs, and to put pressure on the central government and the Hong Kong government,” she said.