The value of North Korea's nuclear declaration depends on its contents and is only one step in the process of stripping the country of its atomic weapons, Japan's foreign minister said Thursday.

• North Korea Submits Nuclear Declaration to China

Masahiko Komura responded cautiously to the declaration of North Korea's nuclear programs, in part because Tokyo is frustrated by the lack of progress on demands that Pyongyang resolve its kidnappings of Japanese citizens.

"It's good that they made the declaration, but the issue is what's in it," Komura said on the sidelines of the Group of Eight foreign ministers' meeting in Kyoto. "We must thoroughly examine the contents."

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North Korea is by far Japan's leading security concern. Tokyo and the rest of the country is well within range of North Korea's ballistic missiles, and Komura said he would have preferred a broader declaration from Pyongyang.

"It would have been better if the declaration had included nuclear weapons," he said. "The important thing is that this is just a step. We must verify whether the declaration will contribute to the complete abandonment of North Korea's nuclear weapons."

North Korea has admitted to kidnapping 13 Japanese citizens, presumably to train spies in Japanese language and culture. Pyongyang released five of them in 2002, saying the remaining eight had died, but Japan is demanding proof of the deaths and an investigation into other suspected abductions.

Japan recently announced it would ease some of its sanctions against the regime after it pledged to launch such an investigation, but no timetable has been announced for either action.

The families of missing kidnapping victims said they worried the favorable U.S. reaction to the declaration meant their grievances would be forgotten in the push to get North Korea to give up its atomic bombs, despite U.S. President George W. Bush's pledge Thursday not to let that happen.

• Bush Offers Carrots for North Korea Nukes Declaration

"It made me realize how Japan lacks diplomatic power," Teruaki Masumoto, whose sister was abducted by North Korea, told national broadcaster NHK. "I am extremely worried all our efforts will become futile."

Sakie Yokota, the mother of Megumi Yokota, who was abducted by North Korea in 1977 while still in junior high school, urged the United States not to abandon the victims.

• TRANSCRIPT: Bush Discusses North Korean Nuclear Announcement

"I would like to ask them not to betray us, our feelings. Mr. Bush, please," she said in an interview with NHK. "It is extremely regrettable that the U.S. has moved hastily" to take North Korea off the list of terrorist nations, she added.

U.S. Secretary of State Condoleezza Rice said earlier Thursday that any American actions in response to the declaration would be subject to verification of the North Korean documents.

"Obviously, the weapons and all the programs are going to have to be dealt with and dismantled if we are to have denuclearization and it's going to have to be done so verifiably," Rice told reporters in Kyoto, Japan, where she was attending a meeting of foreign ministers from the Group of Eight industrialized nations. She next travels to South Korea and China.

Click here to read full remarks from Secretary of State Condoleezza Rice on North Korea.