MOSCOW, Oct. 25 - Russia, Ukraine and Europe need cooperation to ensure the security of natural gas deliveries, International Energy Agency chief Nobuo Tanaka told journalists in response to a question about an asset swap between Russian Gazprom and Ukrainian Naftogaz Ukrayiny.

"The cooperation of Russia, Ukraine and Europe is important in order to resolve the transit issue," Tanaka said.

Asked about demand for gas to be delivered on the planned Nabucco and South Stream pipelines, Tanaka said implementation of the projects will depend on their profitability.