The US president left Beijing for South Korea, where he was due to meet President Lee Myung-Bak on Thursday for talks on North Korea´s nuclear weapons programme and a stalled bilateral free trade pact.
Obama and Wen hailed their countries´ willingness to build a new, in-depth partnership as they sat down for discussions and a working lunch in Beijing, echoing comments made Tuesday by the US leader and Chinese President Hu Jintao.
"Dialogue is better than confrontation and partnership is better than rivalry," Wen said in his opening remarks.
"I sincerely hope that by making this visit to China, Mr President, we will be able to take the comprehensive, cooperative relationship between the two countries to a new level."
Obama noted that the Sino-US relationship was "now expanding to deal with a whole host of global issues in which US-China cooperation is critical".
The US president -- accompanied by his secretaries of state, commerce and energy and the country´s trade representative -- had been expected to raise economic issues such as the yuan, which Washington sees as undervalued.
North Korea´s nuclear programme was also considered a likely topic for discussion. Wen last month made a rare visit to the reclusive state, where he was told by leader Kim Jong-Il that Pyongyang was willing to return to disarmament talks.
Obama held the bulk of his formal talks on Tuesday with Hu, after which the leaders of the world´s number one and three economies said they had agreed to pool their global clout to attack a number of tough issues.
The pair vowed to push for a climate change deal, called on North Korea to return to multilateral talks on ending its nuclear weapons programme and emphasised the need to resurrect the global economy from the depths of crisis.
But few concrete agreements emerged from the talks and differences were obvious in the two leaders´ statements on Iran, pressing economic issues such as the value of the yuan and Tibet -- an extremely sensitive subject for China.
Yet Obama on Tuesday said Sino-US ties have "never been more important to our collective future", adding that the world was facing immense challenges that "neither of our nations can solve by acting alone".
Both presidents spoke about building a "positive, cooperative, and comprehensive" relationship -- using the exact same phrase.
Obama has invited Hu to visit the United States in 2010, and Hu has accepted.
Aides to the US president -- whose stop in China was the third and longest leg of his four-nation tour of Asia -- have stressed that he is working on a relationship that will be invaluable for the future.
US Ambassador to China Jon Huntsman said Obama was "extremely effective" in his private meetings with Hu, parliamentary speaker Wu Bangguo and other officials.
And Jeffrey Bader, Obama´s top White House East Asia aide, said the trip had been "highly successful in setting out and accomplishing the objectives that we had set for ourselves" and an "important first step in building a partnership".
But Obama´s signature charisma and oratory flair were stifled during the visit, with his message -- especially his call for Internet freedoms -- kept from reaching the masses by China´s tight controls on the media and the web.
One of the US president´s last views of China came from atop the Great Wall -- a treasured Chinese landmark like the Forbidden City in Beijing, which Obama visited on Tuesday.
He called the wall "spectacular" and said it stood as a "reminder of the ancient history of the Chinese people".
"It gives you a good perspective of a lot of the day-to-day things. They don´t amount to much in the scope of history," Obama said.
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