Iran has stopped oil supplies to six European countries in response to the latest sanctions imposed by the European Union against its energy and banking sectors, Iran's state-run Press TV reported on Wednesday. The Iranian Foreign Ministry on Wednesday summoned the ambassadors of France, Italy, Spain, Greece, Portugal and the Netherlands in Iran to inform them about the Islamic Republic’s intention to stop oil supplies. Iran supplies most of its Europe-bound oil to Greece, Italy and Spain, which account for about 68 percent of crude imports from the Islamic Republic. In 2011, EU countries purchased an average of 600,000 barrels of oil per day form Iran. The EU voted in late January to ban oil imports from Iran. The move came after the Islamic Republic announced that it had launched a nuclear enrichment program at a well-protected underground facility near the holy Shia city of Qom. The program envisages enriching uranium to the 20-percent level, which can easily be turned into fissile warhead material. The embargo is set to come into force in summer but Iran has said it may cut crude oil shipments to Europe early and warned that the EU embargo on oil imports from Iran may push world oil prices to $150 per barrel. Western nations suspect Iran, which is already under numerous international sanctions, of pursuing a secret nuclear weapons program but Tehran insists it needs nuclear power solely for civilian purposes. Iran has threatened to retaliate by blocking the Strait of Hormuz, the main export route for supplies from the Middle East. The International Monetary Fund warned on Thursday that sanctions on Iran could push oil prices up 20-30 percent to $140 per barrel unless alternative supplies from developing countries came on line.