The city in southern Japan last month invited dozens of countries and territories to the Aug 9 event on the anniversary of the US nuclear bombing in 1945.

Nagasaki mayor Shiro Suzuki told reporters the decision was “not politically motivated” but based on a desire to “hold the ceremony in a peaceful and sombre atmosphere”.

The city had been holding off inviting ambassador Gilad Cohen due to the “potential risk of contingencies” arising from “various developments worldwide around the present Middle East situation”.

Concerns over that risk still persist, Suzuki said, describing Cohen’s exclusion as a “very tough decision”.

Last month, Suzuki said Nagasaki had sent a letter to the Israeli embassy calling for an “immediate ceasefire”.

The ambassador, for his part, called today’s decision “regrettable” and said it “sends a wrong message to the world”.

“As a close friend and like-minded nation of Japan, Israel has attended this ceremony for many years to honor the victims and their families,” he wrote on social media platform X.

Israel launched a blistering military offensive in Gaza last year, following an attack by Palestinian resistance group Hamas on the country.

The Hamas attack on Oct 7 resulted in the deaths of 1,197 people in Israel, most of them civilians, according to an AFP tally based on official Israeli figures.

More than 39,400 Palestinians, mostly civilians, have been killed in the Gaza Strip since the war broke out, according to data provided by the health ministry of Hamas-run Gaza.

Hiroshima has invited Israel to its ceremony but in its letter called for a “ceasefire as soon as possible and resolution through dialogue”, a city official said.

Around 140,000 people died in Hiroshima and 74,000 in Nagasaki when the US dropped atomic bombs on the cities in August 1945, leading to the end of World War II.