China's sweeping maritime claims in the South China Sea are rejected by several members of ASEAN, which have competing claims in the busy waterway.
At the summit in Bangkok, Li cited progress on a long-awaited South China Sea code of conduct, due for completion within three years.
“We are willing to work with ASEAN, under the consensus that had been reached, to sustain long term peace and stability in the South China Sea, according to the timetable set for three years,” Li said in a statement, Reuters reported.
A legally binding code has long been a goal for ASEAN members sparring over what they see as China's disregard of sovereign rights and its obstruction of their energy exploration and fishing.