China has the legitimate right to land a plane on its own territory, and Japan is merely sensationalizing the issue for political gain, experts said after Tokyo expressed concerns over the landing of a Chinese plane on an island in the South China Sea.

China has indisputable sovereignty over the Nansha Islands and their adjacent waters, foreign ministry spokesperson Hua Chunying reiterated on Modnay.

Japan's Foreign Minister Fumio Kishida told a press conference on Monday that Japan is "gravely concerned" over the landing of a Chinese plane in Yongshu Reef of Nansha Islands, and "Japan cannot accept [the act] which is escalating tensions [in the region]," the Kyodo News Agency reported on Monday.

China has completed the construction of an airport on Yongshu Reef, Hua said on Saturday, adding that "the Chinese government conducted a test flight to the airport with a civil aircraft in order to test whether or not the facilities on it meet the standards for civil aviation. Such activities fall completely within China's sovereignty."

"It is another often-played move from Japan to trumpet the 'China Threat' and stir up an 'anti-China chorus [with other countries,]'"Liu Jiangyong, vice director of the Modern International Relations Institute at Tsinghua University, told the Global Times.

Japan's "concern" was indiscreet, as China did not land the plane on a foreign land or on Japanese territory, Liu said.

Besides, it is a civilian aircraft and not a military plane, Liu added.

The airport could conduct rescue and relief work for the benefit of other countries, Lü Yaodong, director of the Institute of Japanese Studies at the Chinese Academy of Social Sciences, told the Global Times.

It could also facilitate scientific research and exploration in the waters, Lü said.

Abe's government intends to hype the issue to win more votes in elections for Japan's House of Councilors in 2016, so as to revise Japan's post-World War II pacifist constitution, Liu added.

China needs to continue to reiterate its stance and take legitimate actions despite such groundless concerns, experts said.

"Japan will continue to cooperate with other countries to protect the freedom of the seas," Kyodo news quoted Kishida as saying. Kishida said the acts do not contribute to a peaceful resolution of the dispute," Japan's public broadcaster NHK reported on Monday.

It could not be more clear who is escalating tensions, Liu said. He added that Japan has been provoking South China Sea-related issues regardless of China's concerns, though Japan is not directly involved in the issues.