The European Union tightened the screws on Iran on Monday as foreign ministers met to slap tough sanctions on its oil sector in a bid to coax Tehran back to nuclear negotiations.

The EU and the United States decided last month to hit Iran with their own sets of measures against the Iranian energy sector, which go beyond a fourth set of UN sanctions imposed over Tehran's refusal to freeze nuclear work.

The last high-level meeting between Iran and the six world powers were held in Geneva in October 2009 when the two sides agreed a nuclear fuel swap that has since stalled.

The new EU sanctions include a ban on the sale of equipment, technology and services to Iran's energy sector, hitting activities in refining, liquefied natural gas, exploration and production, diplomats said.

The EU will ban dual-use goods that can be used for conventional weapons. It will also step up vigilance of the activities of Iranian-connected banks operating in the EU and bar them from setting up branches.

Iran is the world's fourth largest producer of crude oil, but imports 40 percent of its fuel needs because it lacks enough refining capabilities to meet demand.

The unilateral US and EU sanctions are "expected to have a material impact on the country's energy industry," the International Energy Agency said last week, AFP reported.