"This threat is real," he said, but refrained from naming the countries for diplomatic reasons.
The official said terrorism would grow like a malignant tumor if not eliminated.
Al-Mashta said that although Iraq had provided dossiers on the terrorists to the countries where they were hiding, no clear response had followed as to how terrorist leaders managed to get cars loaded with explosives from neighboring countries into Iraq.
"We would like all countries to join the fight against terrorism," the presidential aide stressed.
Speaking about the terrorist threat within the country, Al-Mashta said some of the terrorist groups were made up of remaining members of Saddam Hussein's secret services, which, he stressed, had planned these acts before the overthrow.
"They understand quite well that they cannot take over power, but they spare no effort to thwart Iraq's new authorities," Al-Mashta told journalists after the news conference.
On September 11, the Iraqi government sealed its border with Syria near the Rabiah checkpoint, only allowing vehicles with Interior Ministry-issued permits to cross. Non-residents are barred from the area and civilian possession of arms is strictly forbidden.
Authorities said the crackdown was due to internal security concerns and the need to support the large anti-terrorist operation currently being conducted by U.S. and Iraqi forces 60 kilometers from the border.
Syria dismissed Iraq's accusation that it "exports violence."
