Updated

The U. S. deputy energy secretary says the United States and Russia are planning to enhance cooperation in nuclear reactor design, while maintaining joint efforts to prevent nuclear materials from falling into the wrong hands.

Daniel Poneman said Tuesday after a nuclear energy security working group meeting between the two countries that both nations have developed a "strong partnership" in the field.

Moscow and Washington have launched a joint effort to return fuel from Soviet- and U.S. nuclear reactors built overseas for reprocessing to reduce the danger of highly enriched uranium falling into the wrong hands.

Russia's Rosatom nuclear agency chief Sergei Kiriyenko said it has already removed all highly enriched uranium fuel from Ukraine, and is now planning its retrieval from Uzbekistan and Vietnam.