Britain and the Netherlands urged other EU governments on Friday to join the United States in imposing sanctions on the Lebanese political and militant group Hezbollah for providing support to Syria's President Bashar Assad.

Dutch Foreign Minister Uri Rosenthal said the European Union should brand Hezbollah a terrorist organization, a move that would enable the bloc to freeze the group's assets in Europe.

"We have for quite some time now argued that effective European measures should be taken against Hezbollah," Rosenthal said on the sidelines of a meeting of EU foreign ministers in Cyprus to discuss the EU's response to the Syrian crisis.

The Netherlands considers the Shi'ite Islamist movement, which is a member of the Lebanese government, a terrorist group, while Britain reserves the designation for Hezbollah's armed wing.

British Foreign Secretary William Hague said London would like to see the EU "designate and sanction the military wing of Hezbollah."

But other EU member states, which have blacklisted the Palestinian Islamist group Hamas, have resisted U.S. and Israeli pressure to do the same to Hezbollah.

The powerful group is allied with Iran and was designated by the United States as a terrorist organization in the 1990s.

Several EU countries have argued that such a move could destabilize the balance of power in Lebanon and add to tensions in the Middle East.

Some European diplomats say it would also be legally difficult to blacklist Hezbollah without a court ruling in an EU state that linked the group to terrorism.

"Until now the Europeans have said that to designate a group as a terrorist organization you have to have a judicial process under way against this organization, which is not the case at the present time," said French Foreign Minister Laurent Fabius.

Such a connection might eventually come from a Bulgarian investigation into a deadly bombing of Israeli tourists in a Black Sea resort in July, if the probe confirms Israeli accusations that Hezbollah masterminded the attack with Iran.

Bulgarian Foreign Minister Nikolai Mladenov said the investigation was not yet finished and Bulgaria was not ready to accuse anyone.

"It's moving forward quite rapidly but will take at least another couple of months," he told Reuters. "A report (from such an investigation) needs to be able to stand up in court. This is why we are being very careful in what we say."

Hezbollah and Iran have denied being behind the bombing.

In August, Washington imposed a new round of largely symbolic sanctions against Syria and Hezbollah and said it hoped other countries would take action against the Lebanese group.

The U.S. Treasury said Hezbollah had given training and logistical support to Syria's government. Assad, in turn, provided the group with arms, support and a route for weapons from its main patron, Iran, it said.

Syrian rebels, fighting an uprising against Assad for that last 17 months, also say Tehran has sent its Revolutionary Guards and Hezbollah fighters against them. 

Iran denies giving material support to help crush the uprising.

Hezbollah was set up in 1982 with the help of Iran's Revolutionary Guards to fight Israeli forces which had invaded Lebanon.

Britain, France and Germany also called on Friday for new sanctions against Iran over its nuclear program.