"The political agenda of summits has long been exhausted," Mikhail Ulyanov told RIA Novosti.
Russia participated in every previous Nuclear Security Summit held in Washington, Seoul and The Hague in 2010, 2012 and 2014 respectively.
"If the first summit in 2010 carried meaning because it allowed to attract high-level attention to the relevance of this issue and allowed to give impetus to this work in the international arena and at the national level, it is not entirely clear to us what the meaning of this summit is," Ulyanov stressed.
He specified that the upcoming event "bears a very special nature: it is more for nuclear physicists, for special services, engineers, these are not the topics that should be discussed at the highest level."
Kremlin spokesman Dmitry Peskov upheld on Wednesday the importance of nuclear safety, but explained Putin's absence at the upcoming summit because of a lack of joint efforts and mutual consideration of interests and positions in preparatory works for the event.