EU leaders attending a two-day summit Thursday in Brussels called on Arab countries to play a more active role in dealing with the Libyan crisis.

The European Council "emphasized the key role of Arab countries, and particularly the Arab League," in supporting UN Security Council resolutions and in finding a political solution to the Libya crisis, read an EU statement issued late Thursday night.

The EU would work with the League of Arab States, the United Nations and the African Union to solve the crisis, and will "assist a new Libya economically and in the building of its new Institutions," the statement said, again calling on Libyan leader Muammar Gaddafi to relinquish power immediately.

The statement came as UN-mandated military operations spearheaded by the U.S. and EU members France and Britain against the Tripoli regime entered the sixth night.

But despite nearly a week of continuous air assault, Gaddafi remained defiant, vowing on Wednesday that Western powers engaged in military action in Libya would "end up in the dustbin of history."

The statement said the European Council had noted that "actions taken in conformity with the mandate from the Security Council significantly contributed to protect civilians and civilian populated areas under threat of attack and helped to save lives of civilians."

The military operations will come to an end, when the civilian populations are safe and secure from the threat of attack and the objectives of U.N. Security Council resolutions are met, it said.

So far, EU members including Italy, Denmark, Spain and Belgium have contributed to the coalition forces, but others including Germany remained skeptical.

Moreover, the statement said EU would continue to provide humanitarian assistance to Libya and that the bloc would impose further restrictive measures against Libyan individuals and groups to cut funding off the Tripoli regime.

"The European Union stands ready to initiate and adopt further sanctions, including measures to ensure that oil and gas revenues do not reach the Gaddafi regime," the statement said.

EU slapped a fresh round of sanctions against the Tripoli on Wednesday, targeting individuals and economic entities linked to defiant Gaddafi, including the Libyan National Oil Corporation.

The bloc's sanction list has now included more than 30 individuals as well as economic groups such as the Libya's central bank and the Libyan Investment Authority, the overseas investment vehicle for Tripoli's oil revenues.

In the meanwhile, the European Council on Thursday also noted "with satisfaction" the smooth conduct of referendum on constitutional amendments held in Egypt last week as a significant step towards a more open and democratic political system, the statement said.

It, however, voiced concern at the situation in Syria, Yemen and Bahrain, and urged all parties concerned to engage in constructive dialogues without delay.