Premier Li Keqiang has vowed that China would "resolutely" respond to any provocation from countries with claims on its territory in the South China Sea.
Li told the Boao Forum for Asia on Hainan - the region's version of the World Economic Forum in Davos - that China would stick to a path of peaceful development and maintain friendly ties with its neighbours. But its "determination to protect our territorial sovereignty is unshakable", he said.
"We are willing to settle territorial disputes through peaceful means and we are supportive of joint maritime co-operation, but we will make a resolute response to any provocative moves that affect the peace and stability of the South China Sea," he said.
The disputed waters have become a flashpoint between China and its Southeast Asian neighbours, particularly the Philippines and Vietnam. Brunei, Malaysia and Taiwan also lay claim to parts of the disputed waters, but Beijing insists it owns a large part of the area.
Southeast Asian nations have complained of Beijing's aggressive behaviour in the South China Sea, including cutting the exploration cables of their survey vessels and blocking the passage of ships.
But China has insisted its actions in the disputed waters were legitimate.
Defence Minister Chang Wanquan criticised the Philippines on Tuesday after he held talks with US defence chief Chuck Hagel.
Chang said Manila was "stirring up trouble" by filing a dispute over its claims in the South China Sea with a United Nations arbitration tribunal.
Chang said the Philippines "did the math in the wrong way" - meaning Manila had miscalculated in filing the UN case - and that China would not participate in the arbitration process.
Manila is seeking a ruling regarding its maritime entitlements under the UN Convention of the Law of the Sea, which China has ratified. The Philippines gave more than 40 maps and 4,000 of pages to the tribunal.
"The fact is that it's the Philippines [that is] illegally occupying part of China's islands and reefs in the South China Sea," he said.
Li said in his speech at the forum that stability in the South China Sea was in the mutual interest of China and its neighbours, adding that Beijing was willing to push forward with negotiations for a code of conduct in disputed waters.
Negotiations would also cover other initiatives, such as joint maritime rescue, security dialogue and fighting terrorism.
"China is willing to jointly maintain peace and stability, and freedom of navigation in the South China Sea," he said.