Hong Kong has become one of the avenues used by the United States to "test the edges" and disrupt China's focus to develop its economy, according to a mainland-based political observer.

A senior Beijing official overseeing Hong Kong affairs had warned over the weekend against complacency on safeguarding national security, even though a landmark piece of legislation implemented five years ago has restored peace to the city.

The director of the Hong Kong and Macau Affairs Office, Xia Baolong, told a national security forum that "hostile forces overseas" were still "trying to tamper" with the SAR.

Einar Tangen, a senior fellow at the Taihe Institute and chairman of Asia Narratives, said the country's national security has been attacked on many occasions.

"It's a security of Hong Kong, and it's a security of China," he told RTHK.

"Hong Kong is just part of pattern... It appears that the United States is trying to test the edges to divert Beijing's attention away from its economic development."

But the enactment of the national security law has positioned Hong Kong as the apex of the economic development in the Greater Bay Area.

"The national security law unequivocally affirmed China's sovereignty over Hong Kong," he said.

"It's a very important anniversary, because you can see a lot of changes. Far from being marginalised, Hong Kong has taken a central place in the economic development of the Greater Bay Area."

With Hong Kong celebrating the 28th anniversary of its return to the motherland, Tangen said the SAR is a "linchpin" in the country's development and it should capitalise on its unique position to bring in people from all over the world.

"The future is going to be decided by human resources, not just physical resources. The ability to create products, to understand, to use [artificial intelligence], these are the things that are very important," he said.

"Hong Kong is ideally positioned to attract people from all over the world, especially the Global South, who could come, learn, share and develop ideas."