BEIJING - The first summit between Chinese President Xi Jinping and his U.S. counterpart, Barack Obama, yielded fruitful results and has set a positive tone for the future development of bilateral relations, commented media and experts worldwide.

The two presidents had very good discussions in a uniquely informal atmosphere, Tom Donilon, Obama's national security advisor, told a press briefing after the summit.

"The discussions were positive and constructive, wide-ranging and quite successful in achieving the goals that we set forth for this meeting," said Donilon.

He added that the discussions were quite strategic and covered virtually every aspect of the U.S.-China relationship, including economy, security, cyber attacks and the situation on the Korean Peninsula.

Former U.S. National Security Advisor Zbigniew Brzezinski said he was encouraged by the fact that both leaders, guided by a sense of awareness how important this relationship is to the entire world, were able to discuss issues in a thoroughly business-like fashion and with a constructive effect.

Brzezinski also said that he agreed with the notion that the summit can serve as a start of a process for the strategic rapprochement between the two countries.

Yakov Berger, chief researcher of the Far East Institute of the Russian Academy of Science, said the Xi-Obama summit undoubtedly would boost the China-U.S. ties and lay a foundation for the dialogue between the two countries in the future.

Fernando Reyes Matta, head of the Center for Latin American Studies on China and also a former Chilean ambassador to China, said that Latin American countries are especially interested in the China-U.S. summit, which is beneficial to the China-U.S. ties as well as other countries.

The New York Times reported that Obama and Xi pledged to build "a new model" of relations.

The two presidents "appeared eager to redefine the (U.S.-China) relationship in a way that would allow their countries to overcome their economic, political and diplomatic differences, rather than letting new -- or old -- crises derail progress across the spectrum of issues," it said.

The Washington Post said in an article that Obama and Xi made breakthroughs on some critical issues, including climate change.

The report noted that Obama and Xi agreed to work together to phase down the production of hydrofluorocarbons. U.S. officials and civil societies hailed the agreement as a significant step toward reducing pollution and responding to the threat of global warming, it said.

UN Environmental Program Executive Director Achim Steiner said Sunday that the agreement to target hydrofluorocarbons demonstrated a transformational chapter in international cooperation on climate change.

The China-U.S. move will facilitate the conclusion of a global treaty in this regard, said Steiner in a statement issued in Nairobi, Kenya.

The Itar-Tass news agency quoted Chinese State Councilor Yang Jiechi as saying that the Xi-Obama summit is of strategic, constructive and historic significance, noting the two leaders agreed to build a new model of major-power relations based upon mutual respect, cooperation and win-win results.