The head of Japan's ruling coalition partner Komeito will visit China from Wednesday.
Yamaguchi Natsuo plans to meet senior Chinese officials during his two-day stay in Beijing.
Japan's Chief Cabinet Secretary Matsuno Hirokazu told reporters on Tuesday that the Komeito leader will deliver a letter from Prime Minister Kishida Fumio to Chinese President Xi Jinping.
Matsuno said that Kishida and Xi affirmed they will strive to forge constructive and stable bilateral relations at their recent summit in San Francisco. He said the two leaders agreed to maintain close communication at all levels.
Matsuno added that the government strongly hopes Yamaguchi's trip will help strengthen exchanges and communication between Japan and China.
Yamaguchi spoke to reporters about the death of Ikeda Daisaku, honorary president of the Buddhist organization Soka Gakkai, which is the main supporter of Komeito. Ikeda died last week at age 95.
Yamaguchi stressed that he will work to make sure Ikeda's death will not affect the party's performance in future elections.
He also said he felt there was a strange twist of fate regarding his visit to Beijing, which comes shortly after Ikeda's death, as the late religious leader had devoted himself to promoting Japan-China exchanges.
Yamaguchi pledged efforts to contribute to long-lasting stability and development of the bilateral relations.
Prime Minister Kishida posted a condolence message on social media following Ikeda's death, causing controversy.
Critics called it problematic, citing concerns about the separation of church and state.
But Yamaguchi said he does not see it a problem because Kishida is said to have posted similar messages following the death of Pope Emeritus Benedict XVI.