The mayors of Hiroshima and Nagasaki have visited the US Embassy in Tokyo to request that US President Donald Trump visit their atomic-bombed cities.

Hiroshima Mayor Matsui Kazumi and Nagasaki Mayor Suzuki Shiro met the embassy's Charge d'Affaires ad interim Katherine Monahan for about 20 minutes on Tuesday morning.

The two mayors asked that Trump visit their cities to deepen his understanding of the atomic bombings, and exert leadership toward realizing a world without nuclear weapons.

Monahan reportedly described the hopes of atomic bomb survivors and the two cities for a nuclear-free world as crucial for the future of humanity.

She is reported to have noted that this year would be the perfect time to visit the cities, as it marks 80 years since the end of World War Two, and promised to convey the mayors' request to the president.