WASHINGTON (Reuters) - The White House said on Tuesday it regretted Russia's decision not to attend preparatory meeting last week for the 2016 nuclear security summit.
White House spokesman Josh Earnest did not say Moscow planned to boycott the bi-annual summit itself, which returns in 2016 to the United States, where the process was launched by President Barack Obama four years ago.
"The United States regrets Russia's decision not to participate in last week's preparatory meeting for the 2016 Nuclear Security Summit," Earnest said at a news briefing.
"The door remains open to their continued participation if they were to decide to do so," he added.
The fourth nuclear security summit is scheduled to be held next in Chicago. The summits aim to enhance nuclear security around the world and have involved more than 50 countries including major powers China, France, Germany and Britain.
The last summit was in The Hague in March, when Russia and the United States set aside their differences over Crimea to endorse the meeting's final statement.
Diplomats in Vienna, where the International Atomic Energy Agency is located, offered differing views on Russia's plans.
Two said their impression was that Russia did not intend to take part in the summit, saying Moscow had suggested that such a meeting would not add much value and also had signaled unhappiness with preparations for the summit.
But two others said it was not yet clear whether or not Russia would boycott the summit.
(The story was refiled to fix the wording in next to last paragraph)
Reporting by Doina Chiacu in Washington and Fredrik Dahl in Vienna; editing by Susan Heavey