The statement, read at the end of a rally staged in front of the Swiss Embassy in Tehran (which hosts the US interests section in Iran) today, described the move "as s blatant violation of human rights and naked support for terrorism".
The statement recalled the terrorist nature of the MKO, and underlined that the West's support for the terrorist cult "annuls all the claims raised by the western government about war on terrorism".
The also urged that MKO ringleaders must be tried at international tribunals and receive punishment for their savage crimes.
Late in September 2012, the US State Department removed the MKO from its list of foreign terrorist organizations. The decision made by Secretary of State Hillary Clinton enabled the group to have its assets under US jurisdiction unfrozen and do business with American entities, the State Department said in a statement at the time.
Iran's first reaction came on Saturday when the Iranian Foreign Ministry in a statement condemned the US move and said it displayed Washington's double standard policies.
The statement rapped Washington for applying double standards in dealing with terrorism, reminding that the terrorist MKO is responsible for the deaths of thousands of Iranian civilians.
The delisting of MKO was "a violation of America's legal and international obligations" that could threaten US interests. The decision "will bring US responsibility for past, present and future terrorist operations by this group," the statement said.
Before an overture by the EU, the MKO was on the European Union's list of terrorist organizations subject to an EU-wide assets freeze. Yet, the MKO puppet leader, Maryam Rajavi, who has residency in France, regularly visited Brussels and despite the ban enjoyed full freedom in Europe.
The MKO is behind a slew of assassinations and bombings inside Iran, a number of EU parliamentarians said in a recent letter in which they slammed a British court decision to remove the MKO from the British terror list. The EU officials also added that the group has no public support within Iran because of their role in helping Saddam Hussein in the Iraqi imposed war on Iran (1980-1988).
Many of the MKO members abandoned the terrorist organization while most of those still remaining in the camp are said to be willing to quit but are under pressure and torture not to do so.
A May 2005 Human Rights Watch report accused the MKO of running prison camps in Iraq and committing human rights violations.
According to the Human Rights Watch report, the outlawed group puts defectors under torture and jail terms.
The group, founded in the 1960s, blended elements of Islamism and Stalinism and participated in the overthrow of the US-backed Shah of Iran in 1979. Ahead of the revolution, the MKO conducted attacks and assassinations against both Iranian and Western targets.
Leaders of the group have been fighting to shed its terrorist tag after a series of bloody anti-Western attacks in the 1970s, and nearly 33 years of violent struggle against the Islamic Republic of Iran.
The group started assassination of the citizens and officials after the revolution in a bid to take control of the newly established Islamic Republic. It killed several of Iran's new leaders in the early years after the revolution, including the then President, Mohammad Ali Rajayee, Prime Minister, Mohammad Javad Bahonar and the Judiciary Chief, Mohammad Hossein Beheshti who were killed in bomb attacks by MKO members in 1981.
The group fled to Iraq in 1986, where it was protected by Saddam Hussein and where it helped the Iraqi dictator suppress Shiite and Kurd uprisings in the country.
The terrorist group joined Saddam's army during the Iraqi imposed war on Iran (1980-1988) and helped Saddam and killed thousands of Iranian civilians and soldiers during the US-backed Iraqi imposed war on Iran.
Since the 2003 US invasion of Iraq, the group, which now adheres to a pro-free-market philosophy, has been strongly backed by neo-conservatives in the United States, who argued for the MKO to be taken off the US terror list.
In recent years, MKO ringleaders have been lobbying governments around the world in the hope of acknowledgement as a legitimate opposition group.
The MKO spent huge sums of money over years lobbying for removal from the US terror list, holding rallies in European capitals and elsewhere that featured luminaries like former Homeland Security Secretary Tom Ridge from the administration of George W. Bush. Former House Speaker and presidential candidate Newt Gingrich was among those recently welcomed by the MKO to Paris.
The UK initiative, however, prompted the European Union to establish relations with the exiled organization now based in Paris. The European Court of First Instance threw its weight behind the MKO in December and annulled its previous decision to freeze its funds.
The senior Ayatollah added that by delisting MKO, they want to convey this message that they have stood up against the Islamic Revolution and the whole world knows today that the US is the command center in the fight against the Islamic Revolution.
The MKO is responsible for carrying out numerous acts of terror and violence against Iranian officials and civilians as well as the people of Iraq.
The US formally removed the MKO from its list of terror organizations last Friday; one week after Secretary of State Hillary Clinton sent the US Congress a classified communication about the move.