A member of Catherine Ashton's office, the high representative of foreign policy for the EU, confirmed to Al Jazeera that the decision to go ahead with sanctions was ratified by all 27 member states.

Our correspondent Nick Spicer, reporting from the sidelines of the meeting in Brussels, said: "There will be a review of sanctions in three months, in May, to see how things are going and then the embargo will begin in full force on July 1.

"The reason for that is so that countries heavily dependent on Iranian oil, namely Greece, Italy and Spain, some of the most ailing members of the eurozone, can find new sources of supply, and secondly, to see what steps Iran is taking to come back to the negotiating table."

Our correspondent says that details regarding freezing the assets of the Iranian Central Bank would be divulged at a news conference expected to take place later on Monday.