European Union foreign ministers are discussing imposing additional sanctions on Syria in response to the continuing killings of protesters by the regime of President Bashar Assad.

The EU has already put sanctions on 56 Syrian individuals and 19 organisations in its effort to get Assad to halt his bloody crackdown on the eight-month uprising, and has banned the import into the EU of Syrian crude oil.

"We have adopted a wide range of sanctions already, but I think there's a very good case to add to those," British Foreign Secretary William Hague said Monday on his way into the meeting of EU foreign ministers in Brussels.

The 27 foreign ministers will also likely express "a great deal of concern" over a new report from the International Atomic Energy Agency indicating Iran's nuclear programme includes clandestine efforts to build a bomb, said EU foreign policy chief Catherine Ashton.

Dutch Foreign Minister Uri Rosenthal declined to rule out a military strike in Iran.

"I think that we are talking about stepping up sanctions, that's for sure," Rosenthal said on his way into the meeting. "It should be through the United Nations, if possible at all. And I don't think that we should exclude any other options at the moment. We don't talk about it, but to include or exclude any other options is not in order right now."

But German Foreign Minister Guido Westerwelle rejected any talk of military intervention.

"We think this is counterproductive, we are against it, we warn against talking about it," Westerwelle said. "Iran has the right to use nuclear power peacefully. But it is Iran's duty to abstain from nuclear arming and to make this clear in a transparent manner, so that it is possible to assess it."