France, Germany and Britain on Monday urged Iran to engage in serious and meaningful negotiations, after the European Union (EU) announced further sanctions against Iranian oil exports and central bank.

In a joint statement, French President Nicolas Sarkozy, German Chancellor Angela Merkel and British Prime Minister David Cameron called on Iranian government to immediately suspend nuclear activities and abide fully by its international obligations.

The three leaders made clear that their actions were not targeted at the Iranian people. Instead, they blamed Iranian leadership for failing to restore international confidence in the exclusively peaceful nature of its disputed nuclear program.

"The door is open to Iran to engage in serious and meaningful negotiations about its nuclear program," the statement said.

"We will not accept Iran acquiring a nuclear weapon. Iran has so far had no regard for its international obligations and is already exporting and threatening violence around its region," said the statement.

"Until Iran comes to the table, we will be united behind strong measures to undermine the regime's ability to fund its nuclear program, and to demonstrate the cost of a path that threatens the peace and security of us all," it said.

To ramp up pressure over the country's much disputed nuclear program, the 27 EU members decided at their meeting in Brussels earlier Monday to ban imports of Iranian crude oil and petroleum products. But the embargo will not take full effect until July 1.

The EU 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.

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