Chief Cabinet Secretary Hirofumi Hirano said Tuesday that Japan has no intention of submitting a joint proposal with South Korea to the United Nations Security Council to seek punitive measures against the Democratic People's Republic of Korea (DPRK) over the sinking of a South Korean warship in March.

The top government spokesman said that should South Korea call for sanctions against the DPRK, Japan has its unequivocal support, however Japan's support would not extend to jointly submitting a proposal to the U.N. seeking action to be taken against the DPRK.

"This is a South Korean issue, so it won't be a joint proposal," but Tokyo will provide strong support to Seoul in dealing with the issue, Hirano told a news conference.

Hirano said Japan "strongly supports" Seoul, but would not be "taking the lead" after South Korean President Lee Myung-bak said Monday that Seoul would take the DPRK to the U.N. Security Council as part of retaliation measures.

Japanese Prime Minister Yukio Hatoyama, however, said Japan should "be at the forefront" if Seoul sought a U.N. Security Council resolution against the DPRK. According to sources close to the matter Japan is currently considering its own response beyond expressing a readiness to support Seoul.

A joint investigation team announced its finding last week that a DPRK submarine fired a torpedo that sank a South Korean naval vessel, the Cheonan, and killed 46 sailors on March 26.

The DPRK has denied the accusation and called for its own investigators to be given access to the evidence.