Prime Minister Yukio Hatoyama voiced appreciation Wednesday for the Japan-U.S. security treaty ahead of next week's 50th anniversary of its revision, saying it is indispensable for Japan's defense.

In an address to some 170 senior Self-Defense Forces officers and Defense Ministry officials, the prime minister asked, "As a nonnuclear power, can Japan defend itself on its own in a world that has countries that remain nuclear states and nations that have ambitions to go nuclear?

"We should be grateful for the presence of the Japan-U.S. security treaty to protect our country," Hatoyama said. "I understand this year will be a very important year to further deepen the bilateral alliance."

Defense Minister Toshimi Kitazawa also stressed in his speech the importance of strengthening Japan-U.S. security ties "to secure peace and safety for our nation."