Japan and the United States on Friday urged world leaders to visit Hiroshima and Nagasaki, the cities destroyed by U.S. atomic bombings in World War II, as they aim to build momentum toward a world free of nuclear weapons.

"Recalling the visit by former President (Barack) Obama to Hiroshima, Japan and the United States call on political leaders, youth, and others to visit Hiroshima and Nagasaki to raise and sustain awareness," the two governments said in a joint statement, referring to the former U.S. president's historic visit in 2016.

The move came after a U.N. conference to review the Treaty on the Non-Proliferation of Nuclear Weapons, scheduled to be held from Jan. 4 to 28 in New York, was put off amid the rapid spread of the omicron variant of the coronavirus. The gathering has been repeatedly postponed from its original date in 2020 due to the pandemic.