BEIJING, April 12 (Xinhua) -- China has lodged solemn representations to Japan on Friday over its negative moves in Washington, according to the Chinese Foreign Ministry.

Liu Jinsong, director general of the Department of Asian Affairs of the Chinese Foreign Ministry, summoned Chief Minister of the Embassy of Japan in China Yokochi Akira to lodge solemn representations and express serious concerns and strong dissatisfaction over Japan's negative moves during the Japan-U.S. summit in Washington and the trilateral summit among the United States, Japan and the Philippines.

China has also lodged solemn representations to the Philippines on the same day over its remarks during the trilateral summit.

On April 11, the leaders of the United States, Japan and the Philippines held their first trilateral summit in Washington and issued a Joint Vision Statement after the summit.

Previously, the United States claimed that this summit and the U.S.-Japan-Philippines cooperation "is not aimed at" China. However, the Statement discusses the South China Sea issue at length, blames China on the East China Sea issue and contains irresponsible comments on the Taiwan question.

"China strongly opposes the practice of bloc politics by relevant countries. We firmly oppose any acts that stoke and drive up tensions, and harm other countries' strategic security and interests. We are seriously against forming exclusive groupings in this region," Chinese Foreign Ministry spokesperson Mao Ning made the remarks when asked to comment on a related query at a regular press briefing on Friday.

She said that Japan and the Philippines have every right to develop normal relations with other countries, but they should not introduce bloc confrontation into this region, still less engaging in trilateral cooperation at the expense of other countries' interests.

"To know whether the trilateral summit and cooperation is truly not aimed at China, the answer is right there in the trilateral statement. What else could it be if it's not a smear and attack against China?" Mao said.

On the Taiwan question, Mao said it is purely China's internal affair, adding that resolving the Taiwan question is a matter of the Chinese own and no one can interfere in it. The biggest threat to cross-Strait peace now is the separatist activities of "Taiwan independence" forces, and external connivance and support for them.

If relevant countries truly care about cross-Strait peace and stability, and want the world to be safe and prosperous, they should uphold the one-China principle, oppose "Taiwan independence" separatist activities unequivocally, and support China's reunification, she said.

"This is the right way to ensure peace and stability in the Taiwan Strait. No one should underestimate the will and capability of the Chinese people to safeguard our sovereignty and territorial integrity," Mao said.

To respond to the South China Sea issue and the East China Sea issue, Mao said that China has indisputable sovereignty over Diaoyu Dao and its affiliated islands and Nanhai Zhudao.

"Our activities in the East China Sea and South China Sea are lawful, justified and beyond reproach," said Mao.

China does not accept relevant countries' groundless accusation and deliberate smears against China on the East China Sea and South China Sea, does not accept the illegal arbitral award on the South China Sea or any unilateral moves based on the award, Mao said.

The situation in the East China Sea and the South China Sea is generally stable, she noted, adding that certain countries keep seeking backing from non-regional countries as they infringe on China's sovereignty and rights, and make provocations at sea.

What they have done has escalated the tensions. Certain country outside the region keep fueling the flame and stoking confrontation. This is flagrant, said the spokesperson.

"Let me stress once again that China will firmly guard its territorial sovereignty and maritime rights and interests, and we remain committed to properly settling bilateral maritime issues through dialogue and consultation with countries directly concerned. And we resolutely oppose non-regional countries' meddling and sowing discords to escalate the situation," Mao said.