TEHRAN, Jan. 8 (Xinhua) -- Iran's influential cleric politician Akbar Hashemi Rafsanjani died of heart disease on Sunday.

File photo taken on June 15, 2005 shows Akbar Hashemi Rafsanjani holds his last running campaign ahead of Iran's presidential election in Tehran, capital of Iran. Iran's influential cleric politician Akbar Hashemi Rafsanjani died of heart disease on Jan. 8, 2017, local media reported. (Xinhua/Xu Jinquan)

Rafsanjani, 82, was hospitalized on Sunday due to a heart attack, but the medication attempts were not successful, local reports said.

In his message on Sunday, Iran's Supreme Leader Ayatollah Ali Khamenei expressed grief over the sudden demise of an old friend, fellow and ally during the 1979 Islamic revolution and close colleague during the post-Islamic revolution period, according to Press TV.

Khamenei said that Rafsanjani's loss is overwhelming and very hard to bear as he was a reliable support for the leadership of the country.

On Rafsanjani's demise, President Hassan Rouhani's administration announced three mourning days. The announcement also said that all the governmental institutions would be closed on Tuesday for the funeral ceremony.

Born in August 1934 in Iran's Bahreman, Rafsanjani was an influential politician, religious scholar and the confidant of Ayatollah Ruhollah Moosavi Khomeini, the late founder of the Islamic Republic of Iran.

He was the head of the Assembly of Experts from 2007 till 2011, but then he decided not to nominate himself for the post. He is also the incumbent chairman of the Expediency Discernment Council of the Establishment.

Rafsanjani was elected chairman of the Iranian parliament in 1981 and served until 1989. He also served as president of Iran from 1989 to 1997. In 2005, he ran for a third term in office, placing first in the first round of elections but ultimately losing to hardline rival Mahmoud Ahmadinejad in the run-off round of the 2005 presidential election.

He has been described as a pragmatic centrist. He supported a free market position domestically, favoring privatization of state-owned industries, and a moderate position internationally, seeking to avoid conflict with the U.S. and the West.

In May 2013, Rafsanjani entered the race for the June 2013 presidential elections, but he was not qualified by the Guardian Council. Instead, he supported the incumbent President Hassan Rouhani.