The ceremony started in the Hiroshima Peace Memorial Park and included a minute of silence at 8:15 am (23:15 on Wednesday GMT), the exact time of the nuclear explosion over the city on 6 August 1945.
“We want the Japanese government to listen to the feelings of the bombing’s survivors and join the treaty”, Matsui said in his speech.
Representatives of 80 countries are taking part in the ceremony, but the number of participants is much lower than in previous years because of the COVID-19 pandemic.
On 6 August 1945, the US Air Force dropped an atomic bomb on Hiroshima, killing up to 146,000 people, and three days later dropped another atomic bomb on Nagasaki killing up to 80,000 people. The attacks on the two Japanese cities have been the only instances of the use of nuclear weapons in armed conflict.