Hong Kong has been named publicly as one of China's "core interests and key concerns" in a warning from China to the United States over territorial issues.
The rare reference surfaced in a military-to-military meeting in Beijing on Tuesday between PLA deputy chief of general staff Sun Jianguo and US undersecretary of defence for intelligence Michael Vickers, the PLA Daily reported.
Mainland experts and Hong Kong politicians said the remarks showed Beijing was very worried about US interference in Hong Kong since the Occupy Central protests.
In listing the core matters, Sun named Hong Kong after Taiwan, but before the East and South China seas and cybersecurity, the report said. "The US should earnestly respect China's core interests and key concerns," Sun said.
The mainland media and some Hong Kong officials have often claimed that "foreign forces" had meddled in the city's politics. US President Barack Obama said in November that the US had no role in the protests, but called for transparent and fair elections in Hong Kong.
In a white paper in 2011, Beijing defined its core interests as national sovereignty, national security, territorial integrity, national unity, stability of its political system and society in line with its constitution, and sustainable socio-economic development.
Renmin University international relations specialist Jin Canrong said Sun's remarks showed that "China does not trust the US, and believes the US is involved in Occupy Central".
Retired PLA major general Xu Guangyu agreed that Beijing was sending a message to the US. "Sun is telling the US to calm down and not to have any illusions about using Hong Kong to stir things up," Xu said.
PekingUniversity international relations professor Jia Qingguo said: "Any attempts to demand independence is an act to split the nation. Beijing will not allow it, and is asking the US not to be involved."
This will only make trouble
But Albert Ho Chun-yan, former chairman of Hong Kong's Democratic Party, said the more high-handed Beijing was towards Hong Kong, "the more Hongkongers will alienate themselves from the mainland and feel closer to Britain and America in terms of core values. This will only create more trouble".
New People's Party lawmaker Regina Ip Lau Suk-yee said Occupy Central and the saga surrounding US whistleblower Edward Snowden had prompted the national security officials to put Hong Kong on the agenda with their counterparts.
Foreign ministry spokeswoman Hua Chunying said she was unaware of the details of the meeting. The defence ministry said only that core interests were defined in the 2011 white paper.