The Japanese and Iranian foreign ministers met on Thursday to discuss the growing tensions in the Persian Gulf.
Japanese Foreign Minister Taro Kono told his Iranian counterpart Javad Zarif that to maintain stability in the region, Iran needs to comply with the 2015 nuclear deal signed with major world powers.
The US has sent a nuclear-powered aircraft carrier and bomber aircraft to the Gulf. In response, Iran announced it was scaling back compliance with the nuclear deal.
With tensions rising, Zarif arrived in Tokyo late on Wednesday and met Kono on Thursday morning.
Kono told Zarif that Japan has serious concerns about the situation. He said he would spare no effort to help ease tensions and resolve outstanding issues.
Kono asked Iran to exercise restraint to prevent tensions from rising further.
Zarif said the escalation of tensions by the US was unacceptable. He described Iran's recent actions as the exercise of its rights within the framework of the nuclear deal.
Zarif expressed eagerness to work with Japan to defuse the situation.
The two foreign ministers confirmed their continued cooperation to resolve outstanding issues based on the longstanding friendship between their countries.