March 9 -- Experts panel acknowledges existence of secret nuclear pacts between Japan and the United States.

March 9 -- Japan's Minister of Land, Infrastructure, Transport and Tourism Seiji Maehara says Ozawa should contemplate stepping down in light of his funds scandal.

March 26 -- Japan's Defense Minister Toshimi Kitazawa tells Okinawa Governor Hirokazu Nakaima that the possibility of Japan sticking to an existing accord with Washington to relocate a U.S. military facility within Okinawa would be close to impossible.

March 26 -- Japanese Prime Minister Yukio Hatoyama says he has no intention of making any changes to Cabinet and will not step down ahead of upper house elections.

March 26 -- Japan's Ground Self-Defense Force (GSDF) expands troop presence in Okinawa.

March 29 -- Japanese Prime Minister says his government was not legally bound to come up with a plan to relocate a U.S. Marine base in Okinawa Prefecture by the end of this month, reneging on his recent promises.

March 29 -- Prosecutors seek two year prison sentence for former state-paid secretary of Japanese Prime Minister Yukio Hatoyama. The aide is charged with falsifying political funds reports at Hatoyama's fund management body.

April 12 -- Hatoyama promises Obama in Washington to resolve Futenma issue by the end of May.

April 18 -- U.S President Barack Obama questions Hatoyama's ability to "follow through" on resolving the issue of Futenma.

April 21 -- Chief Cabinet Secretary Hirofumi Hirano says central government plans to continue to pursue the idea of relocating Futenma in Okinawa to Tokunoshima Island in Kagoshima Prefecture.

April 21 -- Hatoyama renews his commitment to resolving base issue by the end of May.

April 25 -- About 90,000 people rally in Okinawa, calling for Futenma to be moved outside prefecture.

April 27 -- Ozawa to be reinvestigated by the Tokyo District Public Prosecutors Office following a committee saying he merits indictment over his fund management body's alleged false reporting of political funds.

April 27 -- Okinawa mayors and citizens opposed to the Futenma relocation idea stage a sit-in protest in front of the Diet members' buildings in Tokyo.

April 30 -- Minister of Land, Infrastructure, Transport and Tourism Minister, Seiji Maehara, says Ozawa staying on in his position could adversely affect this summer's upper house elections, two other senior ministers say same.

May 4 -- Hatoyama meets Okinawa Governor explains difficulties of moving Futenma out of Okinawa, asks for support.

May 6 -- Hatoyama says his pre-election vow to move the U.S. Marine Corps' Futemma Air Station "at least outside of Okinawa Prefecture," was more of an aspiration than a pledge.

May 7 -- Hatoyama asks in vein for the mayors of Tokunoshima Island in Kagoshima Prefecture to accommodate some of the functions of a U.S. air base in Okinawa.

May 10 -- Hatoyama will likely fail to make good on a promise to resolve the row over the relocating Futenma by deadline, sources say.