"If the Europeans deliver weapons, then Europe's backyard will become terrorist, and Europe will pay the price for it," he was quoted as saying by German daily Frankfurter Allgemeine Zeitung.

Sending weapons to militants would lead to terrorism in Europe, he said according to an interview to appear in Tuesday's edition of the newspaper.

"Terrorists will return, battle-hardened and with an extremist ideology," he was quoted as saying.

Assad pointed to terrorist group of al-Nusra Front, and said: "It represents the same ideology" as al-Qaeda.

Assad also denied US, British and French claims that his forces had used chemical weapons against his people during the escalating conflict in Syria.

"If Paris, London and Washington had any evidence for their claims, they would have submitted it to the global public," said Assad, whose comments were published in German.

"Everything that is being said about the use of chemical weapons is a continuation of the lies about Syria," he added. "It is the attempt to justify more military interference."

Assad added that the charges that his forces had used chemical weapons made no sense if the alleged death toll from their use was 150 people.

"Weapons of mass destruction are capable of killing hundreds or thousands at once. That's why they are used," Assad said.

"It is therefore illogical to use chemical weapons to kill numbers of people that could be achieved with the use of conventional weapons."

Assad also accused countries backing the militant groups, also including Saudi Arabia, Qatar and Turkey, of "a blatant violation of international law and the sovereignty of the country" that aims to destabilize Syria and "create chaos and backwardness".

He accused former colonial powers Britain and France of seeking "lackeys and puppets" in the region but warned that destabilizing Syria would cause regional turmoil.