Iranian President Ebrahim Raisi on Sunday called on Tokyo to release funds that have been frozen in Japan because of US sanctions against Tehran's nuclear programme.
"Delaying the release of Iran's assets in Japanese banks is unjustifiable," Mr Raisi told visiting Japanese Foreign Minister Toshimitsu Motegi, the government website reported.
Japan and to a larger extent South Korea are major exporters of technology, and hold billions of dollars in Iranian assets.
The funds have been frozen since former US president Donald Trump withdrew Washington from a nuclear deal between Iran and world powers and reimposed sanctions against Tehran in 2018.
Washington said in mid-July that it was allowing Iran to use the frozen funds to settle debts in South Korea and Japan, but insisted that it did not allow any to be transferred to Tehran.
Talks between Iran and world powers, in which the US has been indirectly involved, aimed at reviving the 2015 accord have stalled since late June.
Mr Motegi arrived in Tehran early Sunday after visiting Turkey and Iraq during a regional tour, and he will also go to Qatar.
After meeting Mr Raisi, he said that during his visits he had discussed the situation in Afghanistan following the capture of Kabul by the Taliban.
He said he agreed with Iran, Turkey and Iraq on the need to co-operate to avoid Afghanistan becoming a "further destabilising factor".