This reverse migration is worrying and there are strong indications that there is a reverse migration from Iraq to the Arab world, to the Arab countries and all Europe, Rubaie said after meeting with Italian security officials.

He also said he wouldn't be surprised if those involved in the thwarted weekend attacks in London had some connection with al-Qaida and Iraq, a Voice of America correspondent reported.

"If we don't control the security situation in Iraq it will spill over to Europe and to neighboring countries in no time. And it will certainly enflame the whole region," he said.

Rubaie said al-Qaida is centered in Iraq and Afghanistan, which exports terrorists to other Asian countries and called for greater international intelligence-sharing to put down the extremists.