Li's remarks came during a meeting with Gambian President Adama Barrow, who is on his first state visit to China since diplomatic relations were resumed last year.
At its 19th National Congress, the CPC drew up a blueprint for securing a decisive victory in building a moderately prosperous society in all respects, embarking on a new journey to fully build a modern socialist country and realizing the great rejuvenation of the Chinese nation, he said.
Over the past thousands of years, the Chinese people have been united and stuck together through thick and thin, built a united country with various nationalities, developed harmonious relationships between 56 diverse and interwoven ethnic groups and formed a big Chinese family where they keep watch for and help defend each other, Xi said.
Xi vowed to fully and accurately implement the principle of "one country, two systems", Hong Kong people governing Hong Kong and Macao people governing Macao with a high degree of autonomy.
Both sides can share experience in national governance and legislation, promote people-to-people and cultural exchanges and improve the legal environment for pragmatic cooperation, said Zhang, chairman of the NPC Standing Committee.
"We will devote more energy and take more concrete measures in ensuring and improving people's living standards, strengthening and developing new approaches to social governance, resolutely winning the battle against poverty, promoting social fairness and justice and making steady progress in ensuring people's access to child care, education, employment, medical services, elderly care, housing and social assistance," Xi said.