Outgoing Prime Minister Fumio Kishida will skip delivering a speech in the general debate of the U.N. General Assembly when he visits the United States in late September, sources have said.

In the Sept. 24-30 general debate, Japan has been allotted a speech slot on the afternoon of Sept. 26. local time, but Kishida plans to return home by Sept. 27, the day of his ruling Liberal Democratic Party's leadership election, the sources said Friday.

Japan has been negotiating with other countries to change its speech slot, but has not reached a deal. It now seems "difficult" for Kishida to give a general debate speech, an aide to the prime minister said.

Kishida would be the first Japanese prime minister to skip a general debate speech since September 2007, when the country's foreign minister at the time, Masahiko Komura, delivered a speech on behalf of then-Prime Minister Yasuo Fukuda.

It is uncertain whether current Foreign Minister Yoko Kamikawa will attend the U.N. General Assembly session, as she is seeking to run in the LDP leadership election.

Japan's permanent representative to the United Nations, Kazuyuki Yamazaki, may deliver a speech instead.

On Sept. 22, Kishida will leave for his last overseas trip as prime minister. While in New York, he plans to attend a "Quad" summit of Japan, the United States, Australia and India, and to hold bilateral talks with U.S. President Joe Biden and other foreign leaders.