By Justyna Pawlak and Sebastian Moffett
PAPHOS, Cyprus, Sept 7 (Reuters) - European Union heavyweights Britain, France and Germany called on their EU partners on Friday to impose new sanctions against Iran over its nuclear programme.
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 programme 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.
Israel, believed to be the only nuclear-armed state in the Middle East, sees the possibility of Iran developing an atomic bomb as a threat to its existence and has said it may use military means if diplomacy and sanctions fail.
Facing the threat of military action that could engulf the Middle East, negotiators are still looking for ways to salvage diplomacy.
The EU's foreign policy chief Catherine Ashton, who leads the international talks with Iran, is due to speak with Tehran's chief nuclear negotiator soon to decide whether any further steps can be taken.
The six countries will also meet on the sidelines of the United Nations general assembly in New York this month to discuss the issue, diplomats say.
Talks hit an impasse in June in Moscow after Iran refused to stop enriching uranium to 20 percent fissile purity unless international sanctions are eased, a step the six rejected.
Talks about new sanctions in Europe could be complicated, despite strong support by the three heavyweights.
Some smaller EU states are concerned about the economic impact of sanctions on the European economy, struggling with a debt crisis.