BUCHAREST, Romania (Dow Jones)-A top American diplomat said Wednesday that U.S. President Barack Obama wants closer cooperation with Russia on energy issues in the Caspian and Black Sea regions, highlighting a clear break from the Bush Administration's diplomacy in these key energy corridors.

"I hope and think we will make more progress with Russia. We would like to see more engagement with Russia" on various energy issues, including the building of new natural gas pipeline routes in this region, U.S. Special Envoy for Eurasian Energy affairs Richard Morningstar told energy executives and diplomats at a conference here.

Morningstar's comments come just over a week after Obama scrapped plans hatched under the Bush White House for a U.S. missile-defense system that had angered Russia because of its proposed location in Poland and the Czech Republic.

They also come days after a flurry of oil chief executives, including Jim Mulva of Texas-based ConocoPhillips (COP), met with Russian Prime Minister Vladimir Putin and Alexei Miller, head of the country's natural gas giant OAO Gazprom (OGZPY), over possible development plans for Russia's giant Yamal natural gas field in northern Siberia.

The U.S., under both Obama and Bush, has backed a European drive to diversify the region's natural gas supply away from Russia after the country deliberately cut off gas to Ukraine on a handful of occasions the past few years following contract disputes. The move pinched supply to customers in other parts of Europe, which gets most of its Russian gas through pipelines that snake through Ukraine.

The European Union has put its weight behind the proposed Nabucco pipeline project that would bring gas to the continent from the Caspian and Central Asia and, possibly, the Middle East. Russia, which has opposed Nabucco and sees it as a competitive threat, has sought to bypass Ukraine with a handful of other proposed projects, including the so-called South Stream gas pipeline; this pipeline would bring Russian gas across the Black Sea to Europe.

Morningstar said the Obama Administration didn't necessarily oppose the South Stream project but thought it was in all parties' interest that the proposed pipeline was commercially viable, something some analysts have questioned. He reiterated U.S. support for Nabucco. The Bush Administration had opposed South Stream.

But he also admonished Russia to move away from using its energy resources as a political weapon and to align the country's energy industry more on a market basis.

"Russia will continue to be a major player in this region for the foreseeable future and it's in our interest for Russia to increase its oil and gas production, but that is not inconsistent with encouraging competition and diversification of pipeline routes," Morningstar said.

-By Spencer Swartz, Dow Jones Newswires; +44 207 842 9357; spencer.swartz@dowjones.com