President Xi Jinping stressed on Tuesday the need for the Xiamen Special Economic Zone to deepen reform and opening-up across the board, promote high-quality growth and work toward integrated development across the Taiwan Straits.

Xi, who is also general secretary of the Communist Party of China Central Committee and chairman of the Central Military Commission, made the remarks in a letter of congratulations on the 40th anniversary of the establishment of the Xiamen SEZ in Fujian province.

Xi urged the city, where he served as vice-mayor between 1985 and 1988, to adhere to the path of socialism with Chinese characteristics, base itself in a new stage of development, implement the new development philosophy and serve and integrate itself into the new development paradigm.

Xi said the city must take the lead in attaining socialist modernization and make greater contributions to the building of a modern socialist nation and achieving the country's second centenary goal.

Xi commended the SEZ for breaking new ground and conducting innovative practices and making historic strides in various respects, adding that the city has played a unique role in promoting national reunification.

This fully vindicated the Party's decision to set up the SEZ, he said.

A ceremony was held in Xiamen on Tuesday to celebrate the 40th anniversary of the SEZ.

Vice-President Wang Qishan said the success of the zone demonstrated the strength of Party leadership and the socialist system with Chinese characteristics, and showcased the bright prospects of the great rejuvenation of the Chinese nation.

Wang said the city must make new progress in deepening reform, expanding opening-up, pursuing high-quality growth and improving the living standards of the people.

It is important to unwaveringly follow and strengthen the Party's comprehensive leadership of the SEZ, which is a key political guarantee for its development, he added.

Xiamen, a city that is close to Jinmen, a county and small island attached to Taiwan, has seen phenomenal growth over the past four decades.

GDP in the zone surged to 638.4 billion yuan ($100.2 billion) in 2020 from 640 million yuan 40 years ago, and its fiscal income increased from 183 million yuan in 1981 to 135.1 billion yuan last year.

The SEZ has also emerged as a key hub in high-tech sectors and a foreign trade powerhouse, with its total import and export volume reaching 691.58 billion yuan last year.

Cui Yonghui, secretary of the CPC Xiamen Municipal Committee, said Xi had left a precious legacy and key pragmatic outcomes were made during his three-year tenure in the city.

"What is particularly special is that General Secretary Xi, as an important leader, trailblazer and builder of the SEZ during its pioneering period, has shown a special attachment to this land," he said.

As the vice-mayor, Xi led the devising of the city's strategy for social and economic development for the period between 1985 and 2000.

Xi also outlined a key vision for the city to enhance the development of its infrastructure.

When Xiamen hosted the ninth BRICS summit in 2017, the president also urged the city to develop itself into a modern and internationalized metropolis.

Xi's high expectations have spurred the city's officials and residents to shoulder their missions and translate his visions into reality, Cui said.

Zheng Limou, chairman of Amoy Diagnostics Co Ltd, a Xiamen-based molecular diagnostics company, said at the ceremony that the city has stood out for its inclusive environment for innovation.

"Over the past four decades, Xiamen has fostered a business environment that is in line with market principles, the rule of law and international standards, and has strived to create a better climate for innovation and talents," he said.