Iranian Foreign Minister Mohammad Javad Zarif is expected to visit Japan this month, amid a growing rift with the United States.
Multiple diplomatic sources say final adjustments are being made for a visit by Zarif in late August as part of his tour of Asia.
The Iranian government is reportedly requesting meetings with Prime Minister Shinzo Abe and Foreign Minister Taro Kono.
Zarif is expected to detail Iran's position over the tense situation in the Persian Gulf.
The US government wants to form an international coalition that includes Japan, to safeguard shipping through the Strait of Hormuz.
Iran regards the proposal as a hostile act that will raise regional tensions.
Iran has warned that it will step up its uranium enrichment activities early next month, unless it gains some form of economic benefit from a nuclear deal made with six world powers in 2015. The US pulled out of the deal and has imposed new sanctions on Iran.
Diplomatic observers say Zarif is likely to be ascertaining how Japan will respond if Iran increases its moves to enrich uranium.