Europe will "pay the price" if it delivers arms to rebel forces in Syria, President Bashar Assad said in an interview with a German newspaper, extracts of which were released Monday.

"If the Europeans deliver weapons, the backyard of Europe will become terrorist and Europe will pay the price for it," he said in the advance extract of the interview due to be published in the Frankfurter Allgemeine Zeitung on Tuesday.

He also warned that delivering arms would result in the export of "terrorism" to Europe.

In his first comments since the United States announced on Thursday that they would be supplying military aid to rebels fighting for his overthrow, Assad said: "Terrorists will gain experience in combat and return with extremist ideologies." The European Union has also dropped its arms embargo on Syria, allowing France and Britain to arm the rebels.

Asked about claims by the French, British and U.S. governments that Syria has used chemical weapons, the newspaper quoted Assad as saying: "If Paris, London and Washington had even one piece of evidence for their claims, they would have shown this to the world."

Last week, the U.S. said 100 to 150 people had died from detected chemical weapons attacks in Syria but Assad said it would be illogical to use chemical weapons to kill this number of people as conventional weapons could also achieve that.

He said: "We have not said that we possess chemical weapons, nor have we said that we do not possess them."

Asked why he refused to allow United Nations inspectors into the country, he said this would allow them to uncover Syrian security secrets that had nothing to do with its arsenal.

"We are a state, we have our army and we have our secrets. We won't allow anyone to get an insight into these -- not the UN, not France, not Great Britain and not others."

He said the government had been open to dialogue from day one and had not changed its position on this but Turkey, Qatar, Saudi Arabia, France and Great Britain were against dialogue.

He said Syria was, however, prepared to negotiate with the United States, France and Great Britain as well as "their tools - Turkey, Qatar and Saudi Arabia".

Assad signaled he had no intention of stepping down: "Of course you can't desert your country during a crisis ... That would be high treason." He added that it would be a different matter if the people decided he should lose his office.

"The president is not the problem. Other countries want the president to resign to make way for a mercenary chosen by these countries."

Assad's remarks came as Western leaders at the G-8 summit in Northern Ireland criticized Russian President Vladimir Putin for supporting Assad in his battle to crush a two-year-old uprising, setting the stage for what could be a difficult meeting of world leaders over Monday and Tuesday.

Earlier Monday, Moscow, a veto-wielding member of the UN Security Council, said it would not permit no-fly zones to be imposed over Syria.

"I think we fundamentally will not allow this scenario," Foreign Ministry spokesman Alexander Lukashevich told a news briefing, adding that calls for a no-fly zone showed disrespect for international law.

He said Russia did not want a scenario in Syria that resembled the events in Libya after the imposition of a no-fly zone which enabled NATO aircraft to help rebels overthrow Muammar Gadhafi.

Meanwhile a Gulf source said on Monday that Saudi Arabia, a staunch opponent Assad since early in Syria's conflict, began supplying anti-aircraft missiles to rebels "on a small scale" about two months ago.

The shoulder-fired weapons were obtained mostly from suppliers in France and Belgium, the source told Reuters. France had paid for the transport of the weapons to the region.

The supplies were intended for General Salim Idriss, leader of the Supreme Military Council of the Free Syrian Army (FSA), who was still the kingdom's main "point man" in the opposition, the source said.

The Gulf source said without elaborating that the kingdom had begun taking a more active role in the Syrian conflict in recent weeks due to the intensification of the conflict.

A foreign ministry spokesman was not immediately available for comment.

King Abdullah returned to Saudi Arabia on Friday after cutting short a holiday in Morocco to deal with what state media described as "repercussions of the events that the region is currently witnessing".

Diplomatic sources in the kingdom say Riyadh has grown increasingly concerned after the entry of Lebanese Shi'ite militia Hezbollah into the conflict and the subsequent rebel defeat in Qusair.