Cardinal Tarcisio Isao Kikuchi says he is “deeply concerned” about U.S. President Donald Trump’s announcement that he plans to renew nuclear weapons testing for the country.

Kikuchi is the archbishop of Tokyo, the capital of Japan, the only country to be hit by nuclear bombs at the end of World War II in 1945.

The United States has not tested nuclear weapons since 1992.

“Although the details remain unclear, it has been reported that he justified this decision by saying, ‘other countries are doing it, so the U.S. will, too.’ I find this reasoning regrettable, as it runs counter to the global trend toward nuclear disarmament and peace,” the cardinal told Crux.

On Nov. 2, Trump told CBS News’s 60 Minutes the U.S. needs to test nuclear weapons “to see how they work.”

“You know, you do have to — and the reason I’m saying — testing is because Russia announced that they were going to be doing a test. If you notice, North Korea’s testing constantly. Other countries are testing. We’re the only country that doesn’t test, and I want to be— I don’t want to be the only country that doesn’t test,” he said.

“Russia’s testing, and China’s testing, but they don’t talk about it. You know, we’re a open  society. We’re different. We talk about it. We have to talk about it, because otherwise you people are going to report— they don’t have reporters that going to be writing about it. We do,” he said.

The United States invented nuclear bombs during World War II, and bombed Hiroshima on August 6, 1945, and bombed Nagasaki thress days later on August 9. Between 150,000 and 250,000 people were killed in the two attacks, most of them civilians. At the time, the U.S. said the bombings were necessary to end the war, and more people would have died it the conflict continued with conventional weapons.

“As the Catholic Church has long emphasized — as the appeal of Pope Leo — our ultimate goal should not only be the abolition of nuclear weapons, but the elimination of all weapons,” Kikuchi told Crux.

“Some may call this a dream, but we must continue to call for peace through nonviolence. True peace which is realization of the order of God could not be achieved by force but only by mutual understanding, dialogue and care for each other,” the cardinal said.

Trump visited Japan on October 27-29 and noted the “beautiful friendship” between the two countries.

Kikuchi said the visit gave him hope.

“After President Trump’s visit to Japan, I had the opportunity to speak with U.S. government officials, who emphasized that the president sincerely desires peace. If that is true, I sincerely hope he will choose paths other than nuclear testing to demonstrate that commitment and lead the world toward genuine peace,” he added.