Japanese Prime Minister Shigeru Ishiba has decided not to express his views on World War II on the 80th anniversary of its end on Aug 15 but may do so later, government sources said Friday.

Although Ishiba, believed to be relatively dovish, has already decided not to have a prime minister's statement approved at a cabinet meeting, he remains eager to offer his perspective and may do so on another occasion, the sources said.

Speculation is growing that he will make the announcement on Sept 2, the date Japan signed the instrument of surrender, rather than Aug 15, when hostilities ceased, according to the sources.

The government had begun selecting experts for an advisory panel to help draft Ishiba's views, but political events, such as U.S.-Japan tariff negotiations and the July 20 House of Councillors election, led to the postponement of its formation, the sources said.

Recently, Ishiba has faced strong internal pressure within his Liberal Democratic Party to step down following its heavy loss in the upper house election, while also working to implement the U.S.-Japan tariff agreement.

On the anniversary of the end of World War II, Ishiba is expected to deliver a speech at a national memorial service in Tokyo, organized by the government to mourn the war dead, the sources said.

In March, Ishiba visited Iwoto Island, formerly known as Iwojima, the site of a fierce World War II battle between Japan and the United States in the Pacific, for the first time since taking office late last year.

During his campaign speeches for the upper house election, in which his ruling coalition lost its majority in the chamber, he highlighted the impact of air raids across Japan, stressing the importance of learning lessons from the war.

Japan's prime ministers marked the 50th, 60th, and 70th anniversaries with statements that have been scrutinized by Asian neighbors, including China and South Korea, which experienced Japanese wartime aggression.

On the 50th anniversary in 1995, then Prime Minister Tomiichi Murayama, leader of a major left-leaning party, expressed "deep remorse" and offered his "heartfelt apology" for Japan causing damage and suffering to the people of many nations.

In 2015, then Prime Minister Shinzo Abe, a conservative, retained key phrases such as "aggression" and "colonial rule" from the statement a decade earlier and acknowledged Japan's past apologies without offering a new one of his own.

Conservative members of the LDP argue Abe's statement on the 70th anniversary marked the end of "apology diplomacy," contending that comments by Ishiba on the 80th anniversary may be unnecessary.