U.S. President Joe Biden is not expected to visit Nagasaki when he travels to Japan for a Group of Seven summit in Hiroshima in May due to scheduling conflicts, diplomatic sources said Thursday, disappointing citizens who hoped for his trip to the atomic bomb-hit city.

Biden would have been the first sitting U.S. president to visit Nagasaki, which the United States hit with an atomic bomb after dropping one on Hiroshima in August 1945 in the final days of World War II.

Prime Minister Fumio Kishida had hoped he and Biden could send a message from the two atomic-bombed cities toward a world free of nuclear weapons, with concern growing over whether Russian President Vladimir Putin will use such destructive arms in his country's war against Ukraine, the sources said.