Lt General Raymond Odierno has credited Syria for cutting the number of militants crossing into Iraq.
He says there has been a 30 per cent fall.
The occupation forces have now re-opened the Al-Qaim/Abu Kamal border crossing. It had been closed for three years because of claims that Syria was letting militants through.
"We think they can do a bit more but we're pleased with the fact that they are taking some additional responsibility with their own internal security measures," Odierno said. "There's still too many coming across and we would like to see them eliminated completely and we'll continue to ask them to do that."