Russia, which provides around one third of the European Union's oil and gas, sent shockwaves through the international community with its military intervention and annexation of the Crimea peninsula last month.
"Regardless of how the stand-off over Ukraine develops, one lesson is clear - excessive dependence on Russian energy makes Europe weak," Tusk wrote in an article in the Financial Times.
"I therefore propose an energy union. It will return the European Community to its roots." EU precursor the European Coal and Steel Community was formed in 1952.
Such a union should be based on several elements, he said.
The first of these would be the creation of a single European body that would buy gas for the whole 28-nation bloc. Another would be that if one or more EU countries were threatened with being cut off from gas supplies, the others would help through "solidarity mechanisms".
The EU must also help finance gas storage capacity and gas links in the countries most dependent on gas sold by the state-owned Russian gas monopoly Gazprom. The energy union would also seek agreements to buy gas from exporters outside Europe, such as the United States or Australia. It could be transported to Europe by ship in liquefied form, Tusk said.