EU pledges to support Syria peace talks despite arms threat

"Member states have committed publicly not to supply any weapons for the time being," he said, referring to a soft pledge not to supply weapons until 1 August.

He added that the EU is "fully supporting" planned talks in Geneva in July to try and broker an agreement in Syria, although details on the timing and who should participate in talks remain unclear.

"There is no military solution for the Syrian conflict. The only alternative are negotiations," said Van Rompuy.

His words followed Moscow's angry reaction to the EU's decision. Russia argued that it would undermine the July peace conference and claimed that the EU move opened the way for Moscow to supply weapons to President Bashar al-Assad.

For his part, Russian President Vladimir Putin said Moscow was "disappointed" by the EU decision.

“Any attempts to influence the situation by force, direct military intervention are doomed to failure and would be bound to entail serious humanitarian consequences,” he said.

Asked whether Russia had already delivered S-300 air defence systems to Syria, Putin said Moscow "does not want to upset the balance in the region."

"This is one of the best anti-missile defence systems in the world. Probably it is the best. It is very powerful. We signed the contract several years ago and so far it has not been implemented."

The exchange came as a new UN report out Tuesday found that the Syria conflict had reached "new levels of brutality" and that there were "reasonable grounds" to suppose that chemical weapons had been used. The report also urged outside powers not to increase the amount of weapons in Syria.

The Russian and EU leaders' words followed a lacklustre bilateral summit in Yekaterinburg, near the Kazakhstan-Russia border, where the only substantive issue agreed was a deal on monitoring "precursor drugs" - chemicals used to make legal medicines, but also used by criminals to make narcotics.

There was little movement on updating the EU-Russia Agreement, underpinning bilateral relations since the two sides established relations following the collapse of the Soviet Union, or on the sensitive issue of energy relations.

Russia supplies a third of the EU's gas, a fact that allows its energy giant Gazprom to set prices.

There was also no movement on Moscow's wish to have a visa facilitation deal.

The EU has linked the issue to its own demand that Moscow lifts a decree - due to go into force on 1July - that would see sensitive air passenger data passed to Russian authorities.

"The EU is also ready to conclude negotiations on an upgraded Visa Facilitation Agreement, provided technical details are clarified and that future regulations in the area of transport and mobility do not negatively affect our citizens and transport operators," said European Commission President Jose Manuel Barroso in relation to the decree.

However, both sides highlighted good trade relations.

"We are reaching new records," said Barroso, with the latest statistics showing that trade has gone up despite the economic crisis.

EU exports to Russia were worth €123 in 2012, up from €105bn in 2009. Exports from Russia to the EU were €213bn last year up from €178bn in 2009.