Japan said on Monday it will not sign an international treaty that bans nuclear weapons and does not welcome its entry into force next year, rejecting the wishes of atomic bomb survivors in Japan who are urging the government to join and work for a nuclear-free world.

The United Nations confirmed on Saturday that 50 countries have ratified the Treaty on the Prohibition of Nuclear Weapons, paving the way for its entry into force in 90 days.

The announcement was hailed by anti-nuclear activists, but the treaty has been strongly opposed by the United States.

Japan’s Chief Cabinet Secretary Katsunobu Kato said the country shares the goal of achieving a nuclear-free world, but does not think the treaty is the way to go.

“Japan’s approach is different from that of the treaty, and there is no change to our position not to sign it, as we have said,” Kato told reporters on Monday.

“We doubt if support is growing even among non-nuclear weapons states, let alone nuclear weapons states.”

Japan has said that it is not realistic to pursue the treaty with nuclear powers and non-nuclear weapons states sharply divided over it.