Zhou said China's presence in the Latin American region would possibly be affected by rising US influence.

"Big economies like US and China should conduct cooperation and avoid conflicts in the region," Zhou said.

Yuan Zheng, of the Chinese Academy of Social Sciences, noted that decades of US sanctions against Cuba have not lived up to expectations.

"Washington is shifting its strategy from boycotting to influencing Havana," Yuan said. He expressed doubt about the future of the Cuba policy change in the US Congress and said he is wondering if the initiative will survive opposition from Republicans.

Obama could seek some support from moderate Republicans, but "he has to make some concessions on other issues", Yuan said.

China is Cuba's second-largest trading partner after Venezuela. Two-way trade grew 7.9 percent to $1.879 billion last year, according to data from Chinese customs. China's exports of $1.374 billion to Cuba last year included refrigerators, buses, pickup trucks, power generators and other machinery products while Cuba's exports of $505 million to China were mainly nickel, sugar and other agricultural products.

Chinese President Xi Jinping visited Cuban revolutionary leader Fidel Castro in Havana, Cuba, during the last stop on his four-nation Latin American trip in July, where he praised Castro's efforts of promoting China-Cuba relations.

Wednesday's announcement came after Obama spoke with Cuban leader Raul Castro by telephone Tuesday, the first direct contact between the leaders of the two nations in more than 50 years.

Earlier Wednesday, Cuba released Alan Gross, an American subcontractor it had held in captivity in five years on humanitarian grounds. Obama said Gross's imprisonment had been an obstacle for the US to making major policy changes toward Cuba.

Obama said he had instructed Secretary of State John Kerry to initiate talks with Cuba on restoring diplomatic relations with the island country, which were severed in January 1961, and to review Cuba's designation as a state sponsor of terrorism. He added that the US will re-establish an embassy in Havana, the Cuban capital, and high-ranking officials will visit Cuba.

The US is also taking steps to increase travel, commerce and the flow of information to and from Cuba, said Obama, adding that he also looked forward to engaging Congress in discussion about lifting the embargo the US has imposed on Cuba.

US Secretary of Commerce Penny Pritzker, who is attending 25th session of the US-China Joint Commission on Commerce and Trade in Chicago, said in a statement that the historic actions by Obama charts a new course for the two countries and their peoples.

"It will improve the lives of millions and will help spur long overdue economic and political reform across the country," Pritzker said. "Expanding economic engagement between the Cuban people and the American business community will be a powerful catalyst that will strengthen human rights and the rule of law."

"The news is very positive," said United Nations Secretary General Ban Ki-moon. "I would like to thank President Barack Obama of the United States and President Raul Castro of Cuba for taking this very important step towards normalizing relations."

Xinhua and Chen Weihua in Chicago contributed to the story.