As Israel continued to threaten military action against Iran, German Foreign Minister Guido Westerwelle said Tehran's failure to meet international demands to scale back its nuclear work meant the EU should discuss new sanctions within weeks.

"Sanctions are necessary and soon. I can't see there is really a constructive will on the Iranian side for substantial talks," Westerwelle told Reuters on the sidelines of a meeting of EU foreign ministers in Cyprus.

"If they will not come back to the table, then probably the next round is necessary. This is not something for next year, we are talking about next weeks," he said.

He called the inconclusive outcome of three rounds of negotiations this year between Iran and the three EU states, Russia, China and the United States "disappointing".

French Foreign Minister Laurent Fabius said diplomacy was at a standstill. "We will discuss in the next days the details of strengthening sanctions," he told reporters.

Fabius suggested new measures could target the finance, trade and oil sectors, but gave no other details.

The latest round of EU sanctions on Iran, implemented in July, already ban oil imports from the Islamic Republic and isolate its banking sector so it is unclear what additional measures the bloc could impose that would have a harder impact.

The ministers stopped short of listing possible targets.

EU foreign ministers were meeting in Cyprus to discuss issues including the bloc's response to the Iranian atomic program and the crisis in Syria. But they were not scheduled to take any decisions.

The United States is applying increasing diplomatic pressure around the world to isolate the Iranian economy. Canada announced on Friday it was closing its embassy in Tehran.

The sanctions are aimed at forcing Iran to curb the nuclear activities the West believes are aimed at developing atomic weapons capability, an allegation Tehran denies. Iran says its nuclear work is for peaceful energy purposes.

Reuters