Maritime tensions have escalated, with China demanding that Vietnam stop its policy of harassment in the South China Sea following the sinking of a Vietnamese fishing boat.
China has also rebutted comments made by Japan regarding the Xisha Islands and announced the relocation of an oil rig, whose deployment this month led to deadly anti-China riots in Vietnam.
The rig has been moved for second-phase operations that analysts said had long been planned.
The Vietnamese fishing boat sank close to the rig. Chinese foreign ministry spokesman Qin Gang said Vietnam bore sole responsibility with its "insistence on forcefully disrupting China's normal operations and its dangerous actions on the sea".
All 10 crew members from the boat were rescued after the sinking on Monday evening about 31 km from the rig.
China said the Vietnamese vessel deliberately rammed a fishing boat before sinking.
Vietnam claimed that some 40 Chinese fishing boats had surrounded its vessel before one of them rammed it and the boat sank.
"We urge the Vietnamese once again to immediately stop all disruptive and damaging activities," Qin said. "As for how the situation will develop and how China will react, it depends on what Hanoi does."
Vice-Minister of Foreign Affairs Liu Zhenmin reiterated on Tuesday that China would continue to pursue the peaceful settlement of disputes through negotiations.
He said no country should doubt China's determination and will to safeguard the peace and stability of the South China Sea.
Qin said Chinese enterprises had been exploring for oil in waters near the Xisha Islands for more than a decade.