The United States is encouraging Greece to move forward with a pipeline bringing natural gas from Azerbaijan to Europe via Greece, rather than setting its hopes on a different project that would pipe Russian gas through Turkey.

The U.S. State Department's special envoy on energy affairs, Amos Hochstein, said Friday he had discussed energy issues with a number of Greek officials during a visit to Athens and that the two sides "agreed on more than we disagreed."

Greece's left-wing government has expressed interest in a Moscow-backed pipeline project dubbed Turkish Stream that would bring natural gas across the Black Sea to Turkey and from there to Europe, potentially through Greece. The U.S. has been encouraging the Trans-Adriatic Pipeline, which will take Azeri gas from the Caspian Sea to Italy.

Hochstein stressed that while Russia was a major gas supplier for Europe, it was important for Greece and Europe to ensure diverse suppliers.

"Diversification is ultimately the best way to create security of supply," he said. "And that means that you should be allowed to bring in other sources of gas that are non-Russian, just to have competition."

That would also reduce the chances of energy being used for political leverage, he said.

The Azeri gas projects "fulfills that trifecta of what is energy security: new source, new supply, new route," Hochstein said. "And it's not a single country that is dominating the infrastructure and the gas production, it's many companies, different consortiums, different countries ... no one element can bring it down or use it as leverage."

Greece also stresses it wants diverse energy sources — and it sees Moscow as part of that. The government of Alexis Tsipras has made clear it intends to pursue ties with Russia and considers the potential Turkish Stream project attractive.

Speaking after talks with Hochstein, Energy Minister Panagiotis Lafazanis said Athens "supports the passage through our country of a pipeline that will reach the Greek-Turkish border and will have natural gas from Russia."

Lafazanis said "Greece seeks to become a pluralistic energy hub in our region."

Hochstein noted the potential Turkish Stream project was still in the very early stages of planning while the pipeline carrying Azeri gas would provide much faster returns.