Japanese officials are now looking at other countries' responses while taking Tokyo's relations with Washington into consideration before making a decision.
"We are scrutinising details in close communication with the United States and other countries concerned," Foreign Minister Toshimitsu Motegi said at a press conference last week when asked whether Japan would join the board.
The board is an international organisation approved by the U.N. Security Council in November. Its founding members include former British Prime Minister Tony Blair and World Bank President Ajay Banga.
Invitations to join the board have been sent to Japanese Prime Minister Sanae Takaichi and other leaders. More than 25 countries have expressed their intention to participate, according to US media.
When the board was proposed in September, the Japanese government thought that the country could join the organisation if its goal was peace in Gaza.
However, Trump indicated that the board's mission would extend beyond Gaza while expressing dissatisfaction with the United Nations, raising concerns that the board could undermine U.N. functions.
In addition, doubts grow about the mechanism by which Trump will continue to lead the board even after he leaves office.
Major European countries, including Britain, France and Italy, have declined invitations to join the board.
In response, Trump has threatened to impose tariffs on French wine unless Paris participates. He has cancelled an invitation to Canada, which is critical of the United States.
These developments have made Japanese officials cautious about Tokyo's participation in the board.
Japan's "participation is not in sight because there are many uncertainties," a Foreign Ministry official said. A Japanese government official voiced worries about Trump's unpredictability.
However, Japan cannot decline an invitation from the United States, an ally, outright. Tokyo sent Takeshi Okubo, ambassador in charge of Gaza reconstruction, to the board's first meeting last week as an observer.
Tokyo is bracing for the possibility that Trump will directly ask Takaichi to participate when they meet for a summit on March 19.
[Copyright The Jiji Press, Ltd.]