China expelled a Philippine naval gunboat that had intruded into waters near Huangyan Island in the South China Sea, a spokesman said on Tuesday morning.

China Coast Guard spokesman Gan Yu said in a statement that a Philippine navy gunboat on Tuesday insisted on trespassing into the waters adjacent to China's Huangyan Island, despite repeated dissuasion and warnings.

China Coast Guard vessels, after multiple verbal warnings that proved ineffective, lawfully took necessary measures such as following and monitoring, warning off and route controlling, to drive away the Philippine warship, he said.

The operation was conducted professionally, in accordance with regulations, and legitimately, the spokesman added.

Gan said that China holds indisputable sovereignty over Huangyan Island and its adjacent waters, and has sovereign rights and jurisdiction over the relevant waters.

The actions of the Philippine side violated Chinese sovereignty and seriously contravened international law and basic norms of international relations, said the statement, urging the Philippine side to immediately stop its acts of infringement.

China Coast Guard will continue to carry out law enforcement activities to firmly safeguard national sovereignty and maritime rights and interests within Chinese jurisdictional waters, in accordance with the law.

Since early August, the Philippines has frequently violated China's territorial sovereignty by sending official vessels and warships to trespass into waters adjacent to Chinese islands in the South China Sea six times in just two months, including four times at Ren'ai Reef and twice at Huangyan Island.

The Philippines' repeated attempts to send construction materials to repair and reinforce a grounded military vessel in Ren'ai Reef have been thwarted by China Coast Guard, which had conducted necessary measures in response.

On Saturday, a spokesperson of the Armed Forces of the Philippines said that China's claim of indisputable sovereignty over the "West Philippine Sea" is disputable, and its "unfounded" claim and actions in the water area are irresponsible.

In response to the comment, the Chinese Foreign Ministry on Monday reiterated the nation's indisputable sovereignty over the Nansha Islands and their adjacent waters, including Ren'ai Reef, while urging the Philippines to stop provocative practices at sea and groundless smears against China.

Ren'ai Reef has been China's territory since ancient times and it has never been the Philippines' territory, the ministry spokesperson said in a statement.

It is an integral part of China's Nansha Islands geographically, economically, politically and historically, which has been widely acknowledged by the international community and fully accords with provisions on archipelagos in the United Nations Convention on the Law of the Sea, the statement said.

The spokesperson also rebutted the so-called South China Sea arbitration award, calling it "illegal, null and void."

It is legally untenable for the Philippines to claim that Ren'ai Reef is part of its exclusive economic zone and continental shelf based on the award, the spokesperson added.

"China once again urges the Philippines to take China's concerns seriously, stop making provocations and creating troubles at sea, and stop groundless attacks and smears, so as to avoid undermining peace and stability in the South China Sea and harming the common interests of countries in the region," the spokesperson said.