The mayors of Hiroshima and Nagasaki separately sent letters of protest to President Barack Obama on Tuesday after the United States revealed it had conducted an experiment using plutonium to examine the capabilities of nuclear weapons between April and June.
"I just can't stop being angry," Hiroshima Mayor Kazumi Matsui said, pointing out that nuclear testing has been conducted in a nation under Obama who two months ago in Berlin proposed reducing stockpiles of U.S. nuclear weapons by up to one-third.
Nagasaki Mayor Tomihisa Taue said in his letter that the latest testing "let down a lot of people and hurt the sentiment of the bombed places."
He then called on the United States to stop all nuclear tests and take the initiative in abolishing nuclear weapons.
Hiroshima and Nagasaki are the only cities in the world to have been subjected to nuclear attacks.
Hiroshima Gov. Hidehiko Yuzaki also sent a letter of protest to Obama saying the United States is supposed to play a leadership role in worldwide efforts to abolish nuclear weapons, but its action disrupts those efforts.