The Southern Gas Corridor of transit networks is a necessary ingredient for energy security, a joint U.S.-European Union statement said.
European Commission President Manuel Barroso in 2009 said the transit networks envisioned under the system would provide the "building blocks" for regional energy security.
A 2009 move by Russian energy company Gazprom to cut gas supplies through Ukraine because of contractual disputes sparked concerns about Russia's grip on the energy sector. European consumers get about a quarter of their gas needs met by Russia, though most of that runs through the Soviet-era transit system in Ukraine.
"The [joint U.S.-EU Energy] Council reaffirmed the importance of the Southern Gas Corridor to bring gas to Europe," they said in a statement.
Part of the corridor relies on a string of pipeline networks that will tie into the Shah Deniz natural gas field off the coast of Azerbaijan.
Kerry said in a statement both sides had critical work ahead for the sake of European energy security.
"The United States and the EU have a lot of work to do in order to diversify our energy supplies," he said Wednesday.