Japan depends on crude oil imports from the Middle East, most of which transits the strait, located in the Gulf.

Iran has effectively closed the strait in retaliation for US-Israeli strikes, sending countries reliant on the shipping lane scrambling for alternative routes and tapping reserves.

In a telephone interview with Kyodo News on Friday, Araghchi denied the passage was closed, insisting instead that countries attacking Iran face restrictions, while others were being offered assistance.

"We have not closed this strait. From our perspective, the strait is open," Araghchi said according to a Farsi transcript of the interview posted on his Telegram channel.

"It is only closed to ships belonging to our enemies -- countries that attack us. For other countries, (their) vessels can pass through the strait."

He added that Iran was prepared to ensure safe passage for Japan. "They only need to contact us so we can discuss how this transit can take place," Araghchi added.

Japan, the world's fourth-ranking economy is the fifth-biggest importer of oil, with 95 percent of it coming from the Middle East and 70 percent passing through the Strait of Hormuz.

On Monday, Tokyo said it was beginning the release of its strategic oil reserves, among the world's largest.

The country holds reserves equivalent to 254 days of domestic consumption.

Members of the International Energy Agency agreed on March 11 to tap oil stockpiles to cushion the surge in prices caused by the war in the Middle East -- by far the largest-ever response of its kind.