MACAO, Dec. 20 -- Chinese President Xi Jinping said here Saturday that nothing could shake the resolve to advance the practice of "one country, two systems," a basic state policy of China.

"No matter what difficulties or challenges we may encounter, they could never shake our confidence and resolve to uphold the principle and advance the practice of 'one country, two systems,'" Xi said at a grand gathering marking the 15th anniversary of Macao's return to the motherland.

To continue to advance the cause of "one country, two systems" is the common mission of the central government, the governments of the Macao and Hong Kong special administrative regions (SAR), and people of all ethnic groups of the country, including compatriots in Hong Kong and Macao, he stressed.

To firmly uphold the policy conforms with not only the fundamental interests of the country and the overall and long-term interests of Hong Kong and Macao, but also the interests of international investors, Xi told some 1,000 dignitaries including the SAR Chief Executive Chui Sai On and principal officials of the fourth-term government, who were just sworn in.

The president urged unswerving commitment to the fundamental purpose of "one country, two systems" while jointly safeguarding national sovereignty, security and development interests, and maintaining long-term prosperity and stability of Hong Kong and Macao.

"We must both adhere to the one-China principle and respect the differences of the two systems, both uphold the power of the Central Government and ensure a high degree of autonomy in the SARs, both give play to the role of the mainland as the staunch supporter of Hong Kong and Macao and increase their competitiveness," he said.

"At no time should we focus only on one side to the neglect of the other," he said.

"This is the only way leading to sound and steady progress," he said. "Otherwise, a misguided approach from the beginning, just like putting one's left foot into the right shoe, would lead us to nowhere."

Xi asked the SAR governments to govern Hong Kong and Macao and uphold the practice of "one country, two systems" according to law.

The "one country, two systems" policy is vital to ensuring the long-term prosperity and stability of Hong Kong and Macao. It is also an important part of the endeavor to fulfill the Chinese dream of great national renewal, he said.