Radio Farda - U.S. President Donald Trump spoke by phone with Japanese Prime Minister Shinzo Abe about Iran, North Korea, and trade, the White House said late on December 21.
White House spokesman Judd Deere did not offer specifics on the leaders discussions on Iran. Kyodo news service said the call lasted one hour and 15 minutes.
Abe told reporters the conversation took place at Trump's request. It came on the same day that Iranian President Hassan Rouhani completed a two-day visit to Japan in which he asked for Tokyos help to salvage a 2015 landmark nuclear deal.
Japan is the key U.S. ally in Asia and also maintains diplomatic and economic ties with Iran. Abe in the past has attempted to play an intermediary role between the two bitter rivals.
Tensions between Iran and the United States have spiraled after Trump last year pulled Washington out of the nuclear deal between Tehran and world powers.
Washington has since reimposed crippling sanctions on Iran in an effort to halt the countrys nuclear and missile program, while Tehran has gradually reduced some of its commitments under the agreement.
Rouhani was the first Iranian leader to visit Japan in nearly two decades. His trip came after Abe in June became the first Japanese prime minister to travel to Iran in more than 40 years.
At the start of the Rouhani talks, Abe said Japan would do what it can to ensure stability in the Middle East, the source of more than 80 percent of its oil.
Meanwhile, Trump and Abe in their call agreed to continue close communication and coordination, particularly in light of recent threatening statements issued by North Korea, the White House spokesman said.
Washington has attempted to persuade North Korea to drop its nuclear weapons programs, but Pyongyang has demanded that sanctions against its government be lifted first.
With reporting by Reuters, AFP, and Kyodo