TOKYO (REUTERS) - Japanese Prime Minister Shinzo Abe, whose country is embroiled in a row with China over tiny islands, on Thursday quoted former British Prime Minister Margaret Thatcher's reflections on the 1982 Falklands war with Argentina to stress the importance of the rule of law at sea.

"Our national interests have been immutable. They lie in making the seas, which are the foundation of our nation's existence, completely open, free and peaceful," Abe said in a wide-ranging policy speech to parliament in which he also urged Japan to seek to become "No.1" as an economic power.

Abe went on to quote a remark from Thatcher's memoirs, reflecting on the Falklands war, in which she said Britain was defending the fundamental principle that international law should prevail over the use of force.

The war over the remote South Atlantic archipelago began when Argentine troops landed on the Falkland islands on April 2, 1982, and ended 74 days later with their surrender. The conflict killed about 650 Argentine and 255 British troops.

Continuing in his own words, Abe said: "The rule of law at sea. I want to appeal to international society that in modern times changes to the status quo by the use of force will justify nothing."

Tokyo's ties with Beijing chilled sharply after the Japanese government last September bought the rocky islands in the East China Sea, which are controlled by Japan but also claimed by China, from a private owner, sparking violent protests in China.

A flare-up in tensions in the territorial row has raised fears of an unintended military incident near the islands, known as the Senkaku in Japan and the Diaoyu in China.

The United States says the islets fall under a U.S.-Japan security pact, but Washington is keen to avoid a clash in the economically vital region.

Japanese fighter jets scrambled again on Thursday after a Chinese twin-engine turboprop Y-12 aircraft came within about 100 km of what Tokyo considers its airspace over the islands, the defence ministry said. Three Chinese patrol ships briefly entered the disputed waters, the Japan Coast Guard said.

The hawkish Abe, who took office in December after his conservative party's big election win, reiterated in his speech that the islands are Japanese territory, and urged Beijing not to escalate tensions.

He added, however, that Sino-Japanese relations were vital for Japan and said his door was always open to dialogue.

China hit back, saying Beijing did not want to see a maritime incident but accused Japanese leaders of making provocative remarks "from time to time" and playing up the China threat to provoke a military confrontation.

"At the moment, Japan should regulate its own words and deeds, stop issuing erroneous statements, properly handle the Diaoyu islands and other issues, and take practical measures to create conditions for the improvement of bilateral relations," Chinese Defence Ministry spokesman Geng Yansheng told a news conference.

Abe stressed the importance of the U.S.-Japan security alliance days after his summit with President Barack Obama.

Calling the US alliance the axis of Japan's diplomacy and security policies, Abe said: "It is only logical that, in the open oceans, the United States, which is the world's largest marine state, and Japan, Asia's largest maritime democracy, form a partnership, and to fortify this constantly is necessary."