The Israeli ambassador to Japan has not yet been invited to Nagasaki's annual peace ceremony, said city officials who instead sent the embassy a letter calling for a Gaza ceasefire.

The city in southern Japan this week invited dozens of countries and territories to the August 9 event on the anniversary of the U.S. nuclear attack in 1945 that killed 74,000 people.

But "as for Israel, the situation is changing day by day... so we have put sending an invitation letter on hold," Mayor Shiro Suzuki told reporters on Monday.