A speech by a Japanese student peace ambassador at an international disarmament conference in Geneva in August was canceled due to pressure from the Chinese government, Japanese government sources said on Thursday.

The speech by a representative of high school student ambassadors calling for the abolition of nuclear weapons had been delivered at every annual Conference on Disarmament since 2014.

But at the 2017 gathering, China objected, citing rules that allow only government officials to speak, according to the sources.

With Beijing having voiced concerns in the past that Tokyo highlighted the 1945 U.S. atomic bombings of Hiroshima and Nagasaki to present itself as a victim of World War II, it is believed that China pressured for the speech to be quashed for the same reason.

At the past three editions of the conference, a student ambassador representative dispatched by a Japanese civic group gave a speech by registering as a member of the Japanese government delegation for one day.

Between February and May this year, China, a nuclear power and a member of the conference, urged Japan to cancel the planned speech. Its disarmament ambassador said the delegation could request that the high school student is removed and that Beijing will pursue the issue if Tokyo continues with the practice, according to the sources.

Japan reportedly argued that given the advancing age of survivors, involving younger generations will give added momentum in the international community toward a "world free of nuclear weapons" by spreading understanding about the suffering experienced after the attacks.

According to conference rules, it is necessary to obtain a consensus from members to add the high school students to a delegation. Japan abandoned having the student speak because gaining approval was judged to be too difficult.

Instead, a group of 22 high school peace ambassadors was invited to a reception hosted by Japan's disarmament ambassador Nobushige Takamizawa in August.

Nobuto Hirano, a 70-year-old co-representative of the civic group that sponsors the student ambassadors, said the Foreign Ministry did not provide a detailed explanation as to why the speech was canceled.

"If pressure from another country was the cause, at least we wanted to receive a full explanation," Hirano said.

Given Japan did not join a U.N. treaty prohibiting nuclear weapons adopted in July, Hirano had assumed the government canceled the speech because it did not want attention on the issue, he said.

The student peace ambassador program began in 1998 after two high school students in Nagasaki in southwestern Japan visited the United Nations headquarters in New York to bring signatures calling for the abolition of nuclear weapons.

Up to August this year, some 200 students from high schools in Hiroshima, Nagasaki and 15 other prefectures have been selected to serve as peace ambassadors for one year. In recent years, they submitted collected signatures to the United Nations every summer.