US Secretary of State John Kerry ended a visit to China without any breakthroughs on two matters at the top of his agenda - sovereignty tensions in the East Sea and the South China Sea.
The only solid outcome of the trip came in a joint statement issued by the two governments yesterday that vowed closer co-operation on climate change.
Shi Yinhong , a professor of international relations at Renmin University, said: "Kerry's China visit only provided an opportunity for both sides to make clear their differences on these issues."
Jin Canrong, with the same university, said it was expected no consensus on regional issues would be reached during the trip. Instead, the visit was important for Beijing and Washington to prepare for an upcoming meeting between President Xi Jinping and US President Barack Obama at a nuclear security summit at The Hague late next month.
"During this trip, Kerry also reiterated the US invitation for the Chinese navy to join the Rimpac exercise in Hawaii later this year. The US hoped China could send two ships but Beijing has yet to reply," Jin said.
The Rim of the Pacific Exercise is the world's largest international maritime warfare exercise and is hosted by the US Navy's Pacific Fleet.
The United States is also hoping China can use its relationship with North Korea to press for restarting talks over dismantling Pyongyang's nuclear weapons programme. Kerry said Beijing had assured him it was prepared to step up pressure.
In a joint statement yesterday, the two governments said they had agreed on steps to carry out commitments to curb the output of greenhouse gases that trap heat in the atmosphere, including by reducing vehicle emissions and improving the energy efficiency of buildings.
Additional reporting by Associated Press, Reuters