A senior Beijing official on Friday called on mainland enterprises to take part in the Northern Metropolis project as part of efforts to fully back the Hong Kong government.

Zheng Yanxiong, director of the central government's liaison office, told a reception that state-owned companies should also support the SAR in integrating into the country's development.

"I hope state-owned enterprises will make good use of Hong Kong's unique advantages of having the backing of the motherland and being connected to the rest of the world," Zheng said.

"Mainland companies should continue to boost their investment in Hong Kong, and constantly improve their business strategies. They should also proactively take part in the Northern Metropolis development, fully support Hong Kong in consolidating its status as a financial, shipping, and trade centre, and in building an international innovation and technology centre."

Zheng also urged companies to take root in Hong Kong and contribute to society.

At the same event, Chief Executive John Lee described contributions to the Northern Metropolis development as "an investment with good returns" as he called on mainland firms to support the project.

The Hetao Shenzhen-Hong Kong Science and Technology Innovation Co-operation Zone, located within the metropolis area, is an important platform for collaboration in the Greater Bay Area, Lee added.

"The government will be innovative and use creative thinking to combine market forces, to promote the development of the Northern Metropolis, including that of the co-operation zone, so as to allow the first batch of industries to enter the region as soon as possible," he said.