An Iranian security speed boat passes along the Kalntari oil dock in the Sea of Oman near the strait of Hormuz in the city of Chabahar, south-eastern of Iran,?Jan. 17, ?2012. [CFP]

The European Union (EU) on Monday imposed further sanctions against Iranian oil exports and central bank, a move aimed to ramp up pressure over the country's much disputed nuclear program.

According to an EU conclusion, the 27-member block banned imports of Iranian crude oil and petroleum products.

However, to protect the vested interests of European companies, the conclusion gave countries with "already concluded contracts" with Iran until 1 July 2012 to carry out the embargo. A review of the measures relating to oil and petroleum products will take place before May 1, 2012.

The conclusion also outlawed exports of key equipment and technology for the petrochemical sector to Iran, new investments in petrochemical companies in Iran, as well as joint ventures with such enterprises.

The EU currently purchases nearly 20 percent of Iranian crude exports, with countries such as Greece and Italy most reliant on its oil.

Gulf nations such as Saudi Arabia have offered to step up its own production to compensate for any shortfall caused by the ban on Iranian oil.

"The EU is already engaged in too many economical issues to allow it to spend that much time in trying to convince other countries not to buy Iranian crude," Amanda Paul, an analyst at the European Policy Center, told Xinhua.

Meanwhile, the EU froze on Monday the assets of the Iranian central bank within the EU, while ensuring that legitimate trade can continue under strict conditions.

The conclusion said that trade in gold, precious metals and diamonds with Iranian public bodies and the central bank would no longer be permitted, nor would a number of additional sensitive dual-use goods may be sold to Iran.

The 27-member body also subjected three more persons to an asset freeze and a visa ban. It also froze the assets of eight further entities.