Japanese Foreign Minister Taro Kono said he urged Iran to abide by a 2015 nuclear deal during a meeting on Tuesday with his Iranian counterpart, Mohammad Javad Zarif. The men agreed to maintain close communication between Japan and Iran, which historically have had friendly ties, to ease tension between the United States and Iran, Kono told reporters in Tokyo afterward. "Based on Japan’s stance of consistently supporting the nuclear agreement, I asked the Iranian side to observe the agreement, to go back immediately to the commitments of the agreement, and to refrain from taking measures that would infringe on the agreement," Reuters quoted Kono as saying. President Donald Trump pulled the United States out of the 2015 agreement last year and reimposed sanctions on Iran. In response, Iran has slowly been breaching its side of the deal, under which Tehran agreed to curbs on its nuclear program in exchange for the lifting of many international sanctions. The standoff over the nuclear deal has caused a sharp increase in tensions between the two longtime foes. At the start of the meeting, Zarif and Kono smiled and shook hands. Zarif said Japan and Iran have special interests in the security of the energy market and stability in the Gulf. Kono declined to say if the two discussed the US-led mission to bolster Gulf security or purchases of Iranian crude oil. Washington has been calling for its allies to join it in an operation to guard shipping in the Strait of Hormuz. So far, Britain, Australia and Bahrain have joined the US-led security mission. French President Emmanuel Macron opened an avenue towards a diplomatic solution to the US-Iran standoff at a Group of Seven summit in France at the weekend, saying that Iranian President Hassan Rouhani had told him he was open to a meeting with Trump.