As China embarks on its reform and opening up in the new era, Hong Kong and Macao still have "unique" status and strengths, and can still play "irreplaceable" roles in the process, Chinese President Xi Jinping said on Monday when meeting with delegations of the two special administrative regions (SARs) in Beijing.

Led by Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor and her Macao counterpart Fernando Chui Sai-on, the over 200-member delegations were visiting the mainland to mark the 40th anniversary of China's reform and opening up – a landmark program that has transformed a poor nation into the world's second largest economy.

Xi called on Hong Kong and Macao to embrace the country's reform and opening up, seize opportunities arising from the Belt and Road Initiative and the Greater Bay Area plan, and integrate themselves into the nation's development, in order to achieve better development in the two regions and contribute to China's great national rejuvenation.

Proposed by Xi in 2013, the Belt and Road Initiative comprises the Silk Road Economic Belt and the 21st Century Maritime Silk Road, and aims to build trade and infrastructure networks connecting Asia with Europe and Africa along and beyond the ancient Silk Road routes.

The Greater Bay Area, formally known as the Guangdong-Hong Kong-Macao Greater Bay Area, covers Hong Kong and Macao as well as nine cities in south China's Guangdong Province. Two signature projects in the Greater Bay Area – the Hong Kong Section of the Guangzhou-Shenzhen-Hong Kong High Speed Rail and the Hong Kong-Zhuhai-Macao Bridge – have recently been completed, connecting the two SARs more closely with the mainland.

Hailing the contributions made by Hong Kong and Macao compatriots to China's reform and opening up over the past four decades, Xi stressed that the "One Country, Two Systems" principle is the "biggest strength" of the two SARs, the nation's reform and opening up is their "biggest stage," and the implementation of national strategies such as the Belt and Road Initiative and the Greater Bay Area plan is creating "significant opportunities" for them.

Lam and Chui attributed the two region's prosperity to the nation's reform and opening up and spoke highly of the "One Country, Two Systems" principle.

"As the nation further opens up to the world, the status and roles of Hong Kong and Macao will only be strengthened, not weakened," Xi said, urging the two SARs to be more actively involved in the country's comprehensive opening up.

He expressed hopes that Hong Kong and Macao can facilitate the engagement of capital, technology and talents in the country's higher-quality development and opening up. Underscoring the two SARs' strengths in terms of extensive international connections and advanced professional services, the president called on Hong Kong and Macao to work more closely with the mainland, which boasts a vast market, a comprehensive industrial system, and technological strengths in many areas.

Xi said Hong Kong's status as international financial, shipping and trade centers should be boosted and he called for more efforts to build the city into an international hub for innovative technology.

On the other hand, he urged Macao to enhance its position as a tourist and recreational center in the world. The city should improve its role as a service platform for business cooperation between China and Portugal, he added.

Moreover, Xi called on Hong Kong and Macao to be more proactive in integrating themselves into the development of the whole nation, take a more active part in national governance, and further promote international cultural exchanges.

Chinese Vice Premier Han Zheng also attended the meeting.

Hong Kong returned to China from British rule on July 1, 1997, followed by Macao's return to the motherland from Portuguese rule on December 20, 1999. Under the "One Country, Two Systems" formula, the main body of China adheres to the socialist system while capitalism is retained in its two SARs.