Vice Foreign Minister Takeo Akiba did not rule out the possibility of a nuclear weapons storage site being built in Okinawa Prefecture in comments he allegedly made in 2009 when he was a minister at the Japanese Embassy in Washington, a U.S. researcher said Monday.

Gregory Kulacki, China project manager at the U.S.-based Union of Concerned Scientists, cited a document he obtained dated Feb. 27, 2009, that summarized Akiba's remarks at a U.S. congressional commission that year.

In response to a question on how Japan might view the construction of a nuclear weapons storage site in Okinawa or Guam, Akiba "stated that he found such a proposal persuasive," according to the document.

In Tokyo, however, Foreign Minister Taro Kono denied that Akiba had made such a remark.

"The government has firmly maintained the three nonnuclear principles" of not possessing, not producing and not allowing the introduction of nuclear weapons into Japan, Kono said.