The EU signed a series of agreements for oil and gas projects with Iraq at a ceremony in Baghdad.
A January 2009 dispute between Moscow and Kiev forced Russian gas giant Gazprom to cut gas supplies to Ukraine. That row exposed vulnerabilities in the European energy sector as 80 percent of its gas from Russian travels through Soviet-era pipelines in Ukraine.
The EU aims to diversify its energy sector through the Southern Corridor projects, which include the Nabucco pipeline through Turkey, the White Stream project from Georgia and the Interconnector between Greece, Turkey and Italy.
"Iraq represents a vital link for EU's security of supply," said outgoing European Energy Commissioner Andris Piebalgs. "It is already an important supplier of oil and can become a key gas supplier for the Southern Corridor."
The EU said a series of agreements with Baghdad strengthens Iraqi President Jalal Talabani's commitment to the Southern Corridor expressed in 2009.
With vast natural gas resources and the third-largest oil reserves in the world, Iraq could become the energy bridge between the Middle East, the Mediterranean and Europe, the EU said.