This was stated by Ben Rhodes, deputy national security adviser to the White House National Security Council, in a conference call with reporters, Censor.NET informs citing Reuters.
"Russia's decision to certainly not participate at a high level we believe is a missed opportunity for Russia above all," Rhodes said.
"Frankly, all they're doing is isolating themselves in not participating as they have in the past," Rhodes said, noting the United States and Russia continue to cooperate and discuss issues related to nuclear security.
As explained earlier by Russia's Foreign Ministry speaker Mariya Zakharova, "there are no objectively arising breakthrough decisions in the international cooperation on physical nuclear security that would demand involvement of heads of states and governments."
The Nuclear Security Summit is scheduled for March 31- April 1. President of Ukraine Petro Poroshenko intends to deliver a speech at the summit on April 1, his press secretary informed.