Afghan President Hamid Karzai is on his first visit to Hiroshima today ahead of the 65th anniversary of the US atomic bombing of the western Japanese city in World War II.
Donning his traditional ethnic costume, Karzai laid a wreath at the cenotaph for the atomic bomb victims and in Peace Memorial Park, local media reported.
After inspecting the ground zero areas, he said he learned from Hiroshima that acts of atrocity must not be repeated, the Kyodo News agency reported.
As he heard from an atomic bomb survivor about his experience, Karzai also said that the use of atomic bombs cannot be justified under any circumstance, Kyodo said.
In Hiroshima, more than 140,000 people were killed instantly or died in the days and weeks after the August 6, 1945 attack.
Three days later, a second atomic bomb was dropped in Nagasaki. Japan surrendered on August 15, ending the war.
Karzai, on his first visit to Tokyo since he started his second term in November after an election widely criticised for rigging, thanked new Prime Minister Naoto Kan on Thursday for Japan's support.
Japan last year pledged up to five billion dollars in aid by 2013 to rebuild the impoverished country, where US-led and then multinational forces have been battling Taliban insurgents since late 2001.