Vice President Biden applauded the news as a “bright piece of sunshine.”
A bipartisan group of senators asked China to back off its territorial claims in the Pacific.
"Obama's decision to rebalance to the Pacific Basin is not in question,” Biden said.
“He is a very important man. Seriously he is important,” Biden told Li.
Biden said he was "very direct about our firm position" with China's president.
Official approval of the pact by Afghan Defense Minister Bismillah Khan Mohammadi or other members of Karzai's Cabinet could "fulfill the kind of commitment we need" to proceed with postwar planning and operations, Defense Secretary Chuck Hagel said Wednesday.
But "whatever document [Kabul] agrees to ... who has the authority to sign on behalf of Afghanistan" and give the postwar pact the green light is still an open question, the Pentagon chief added.
The Defense Department is shuttering key supply lines in Pakistan, ordering a halt to all military shipments along those routes.
The decision was prompted by security concerns for military and civilian shipping firms moving along the routes, Pentagon spokesman Mark Wright told Reuters on Tuesday.
Vice President Joe Biden and Japanese Prime Minister Shinzo Abe agreed Tuesday that their two nations need to move forward this year toward completing an Asia-Pacific trade deal.
While each leader acknowledged the difficulty in melding priorities for the 12 nations involved in negotiations of the Trans-Pacific Partnership (TPP), they expressed optimism in finding solutions and reaching an agreement as scheduled by year's end.
In a letter to National Security Advisor Susan Rice, Forbes said the administration's guidance to American airliners to adhere to Beijing's demands "creates confusion about U.S. intentions and puts us at odds" with key allies in the Asia-Pacifc region.
The White House's request to commercial airliners to obey China's rules for the so-called Air Defense Identification Zone runs contrary to its orders for American military aircraft, which do not officially recognize the air defense zone.
A top Senate Republican is urging U.S. trade officials to move forward on an Asia-Pacific trade deal with only those countries willing to adopt the highest standards.
Senate Finance Committee ranking member Orrin Hatch (Utah) sent a letter to U.S. Trade Representative Michael Froman on Monday night suggesting that he wrap up work on the 12-nation Trans-Pacific Partnership (TPP) by year's end with those willing to maintain high standards in areas such as intellectual property.