U.N. Secretary-General Antonio Guterres will attend for the first time a memorial ceremony in Hiroshima in August that marks the U.S. atomic bombing of the city in World War II, city officials said Thursday.

It will be the first attendance by a head of the United Nations since Ban Ki-moon did so in 2010. He was also the first U.N. chief to join the event.

Guterres in 2018 attended a similar service in Nagasaki, the other city devastated by an atomic bomb, becoming the first sitting U.N. head to do so.

His visit to Hiroshima will come amid veiled threats by Russia to use nuclear weapons in its war against Ukraine. Guterres will likely deliver a message to rally support for U.N. efforts to eliminate such weapons.

A uranium-core atomic bomb named "Little Boy," dropped by a U.S. bomber, exploded above the city at 8:15 a.m. on Aug. 6, 1945, killing an estimated 140,000 people by the end of that year.

The United States dropped a second atomic bomb on Nagasaki on Aug. 9, and an estimated 74,000 people died from the bombing by the end of that year.