Gholam Reza Aghazadeh, the head of the Iranian nuclear agency, has resigned, Iran's semi-official ISNA news agency reported on Thursday. According to the report, the official gave no reason for his resignation. However, Aghazadeh has been known to be close to opposition leader Mir Hossein Mousavi, whose claims of a rigged presidential election sparked widespread violent protests throughout the Islamic republic last month. Mohsen Delaviz, a spokesman for Iran's atomic energy department, told The Associated Press that Aghazadeh was resigning "after years of efforts in the country's nuclear industry" and would explain the decision himself. Aghazadeh told the semiofficial ISNA news agency he submitted his resignation from Iran's Atomic Energy Organization 20 days ago to President Mahmoud Ahmadinejad, who accepted it. He also resigned from his other post as one of Ahmadinejad's vice presidents, said ISNA. The departure is unlikely to impact the standoff between Iran and the West over the country's nuclear program since Aghazadeh was not involved in negotiations, and ultimately all decisions on policy lie with supreme leader Ayatollah Ali Khamenei In his post, which he held for 12 years, Aghazadeh has pushed steadily ahead with Iran's nuclear program, which the West fears is aimed at developing a nuclear weapon. Iran denies that charge, saying it wants only to generate electricity, and it rejects UN demands it halt uranium enrichment. Aghazadeh in the past year has announced several times Iran's advances in manufacturing centrifuges, a key component of the enrichment program. According to the UN nuclear watchdog, Iran has nearly 5,000 centrifuges currently enriching uranium and another 2,000 others ready to start enriching. Israel, who views Iran as its archenemy and has not ruled out military action to neutralize the country's nuclear program, said it was too early to respond to Aghazadeh's resignation. "We don't know why he resigned, what brought about his resignation and what change this will bring, if at all," Foreign Ministry Spokesman Yigal Palmor said, "So we can't comment." It was not known whether Aghazadeh's resignation was connected to the election dispute. But if Aghazadeh was pushed out or walked away because of differences over the election, it could signal a narrowing base of support for Ahmadinejad and signal that he will have to rely on more hard-line supporters in the new government he will form after his planned inauguration in August. Aghazadeh has made no public comment on the election turmoil, in which Mousavi supporters staged massive street demonstrations before the government crushed them in a heavy crackdown. Aghazadeh has been a close associate of Mousavi ever since Mousavi was prime minister in the 1980s. The outgoing nuclear chief is also close to Akbar Hashemi Rafsanjani, a powerful cleric and former president who is a bitter rival of Ahmadinejead. Aghazadeh was among a group of pro-Rafsanjani officials who formed a political party, Kargozaran, in the early 1990s. There have also been hints of behind-the-scenes differences between Aghazadeh and Ahmadinejad's energy minister over the planned opening of Iran's first nuclear plan at Bushehr, whose opening has repeatedly been delayed. On Wednesday, Energy Minister Parviz Fattah complained that despite plans to start up Bushehr this summer, "so far, head of Iran's Atomic Energy Organization has not provided any information" on inaugurating it. The comments could suggest that Aghazadeh was resisting a rushed start to the reactor, which is being built with Russian aid.