Geneva, June 11 (RHC)-- The UN nuclear agency's chief says he is "worried about increasing tensions" over Iran's nuclear program, calling for de-escalation efforts as Tehran expresses dissatisfaction with European actions to offset the effects of the US withdrawal from a 2015 international deal.

The Director General of the International Atomic Energy Agency Yukiya Amano said on Monday in a speech to a meeting of the IAEA's 35-nation Board of Governors, one of its main decision-making bodies: "I... hope that ways can be found to reduce current tensions through dialogue."

Iran and the five permanent members of the United Nations Security Council -- the United States, France, Britain, Russia and China -- plus Germany, signed the nuclear agreement, officially known as the Joint Comprehensive Plan of Action (JCPOA), on July 14, 2015 and started implementing it on January 16, 2016.

Under the JCPOA, Iran undertook to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions imposed against Tehran.  However, U.S. President Donald Trump pulled his country out of the JCPOA in May 2018 and re-imposed harsh sanctions against the Islamic Republic in defiance of global criticisms.