The Japanese government said Saturday it "highly appreciates" the newly released Nuclear Posture Review by U.S. President Donald Trump's administration, saying the updated policy helps enhance deterrence amid a worsening security environment partly caused by North Korea's nuclear and missile development.

Japanese Foreign Minister Taro Kono said in a statement that the latest review "clearly articulates the United States' resolve to ensure the effectiveness of its deterrence and its commitment to providing extended deterrence to its allies including Japan."

The Nuclear Posture Review says the U.S. administration will not rule out the use of nuclear weapons in response to non-nuclear attacks against the United States and its allies and partners given the changing security environment.

Victims of the U.S. atomic bombings of Hiroshima and Nagasaki in 1945 say they fear a tragedy will be repeated.

"We'll face greater dangers of nuclear weapons. As someone who knows the horror of a nuclear weapon, I find (the new policy) extremely disappointing," said 83-year-old Shoso Kawamoto in Hiroshima. He lost six family members in the 1945 bombing.

Kono said Japan, which relies on the U.S. nuclear umbrella, "shares with the United States the same recognition of such a severe security environment."

Japan will continue to promote "realistic and tangible nuclear disarmament" with the United States as "a leading state toward the total elimination of nuclear weapons."

The mayors of Hiroshima and Nagasaki separately issued statements protesting the U.S. policy shift.

"We would like President Trump to visit the bombed sites and start to seek a world without nuclear weapon," Hiroshima Mayor Kazumi Matsui said.