Russian President Vladimir Putin attends a National Unity Day event Tuesday in Moscow. (Vasily Maximov/European Pressphoto Agency)

Russia will not attend the 2016 Nuclear Security Summit, an international gathering initiated by President Obama to draw attention to problems of nuclear security and a key component of his nonproliferation agenda, the country’s top diplomat in the United States said Wednesday.

“We are not planning to attend the summit, not because we are not committed to non-proliferation,” Ambassador Sergey Kislyak said. “We do not see added value coming out of these meetings.”

Rather than “preparing another big splash,” he said, Russia would prefer to focus attention on organizations, such as the International Atomic Energy Agency, “that have been created by all of us to deal with these issues.”

Withdrawal from the summit, also announced by the Foreign Ministry in Moscow, is the latest thread in the unraveling of Russia’s relations with the West, particularly with the United States, in the wake of the ongoing Ukraine crisis.

Kislyak, who has been ambassador here since 2008, said he was “disappointed with the state” of U.S.-Russia relations, as well as the way in which Russian President Vladi­mir Putin has been “demonized” by the U.S. media. He spoke in a rare session with American journalists over lunch at his residence, three blocks from the White House.

While Russia is willing to improve relations and continue cooperation on international issues such as terrorism and nuclear negotiations with Iran, he said, “we are not going to beg for dialogue if our American partners do not want it.”

Tensions between Russia and the United States, along with its European partners, flared this year following Russia’s annexation of the Crimea region of Ukraine and its support for separatists fighting against the Western-backed government in Kiev. Relations were further strained over Russia’s decision to grant temporary asylum to former National Security Agency contractor Edward Snowden.

In May, NATO suspended the NATO-Russian Council, its principal vehicle for defense cooperation with Moscow.

President Obama led the imposition of economic sanctions against Russia and has suspended a web of bilateral contacts that were set up as part of what his administration in 2009 called a “reset” of a relationship that had often been strained in the past.

Nearly two dozen bilateral commissions, directed at issues including economics and arms control, have been suspended, Kislyak said, all of them “by the United States, not by us.”

Russia blames the administration for aiding what it considers the overthrow of Ukraine’s legitimate government by opposition demonstrators. Although it has accepted the subsequently elected Ukrainian government of President Petro Poroshenko, Moscow charges that Poroshenko has violated a cease-fire and political agreement reached this summer to allow more autonomy for eastern Ukraine, where Russian-backed separatists have seized territory. The Obama administration charges that the separatists, with Russian arms and support, have violated the agreement by refusing to lay down their weapons and holding their own election this past weekend.

Obama initiated the nuclear security summits following a 2009 speech in Prague in which he described nuclear terrorism as “the most immediate and extreme threat to global security” and called for “a new international effort to secure vulnerable nuclear material around the world.” The first summit was held in Washington in 2010, with subsequent sessions in 2012 in Seoul and this past March in The Hague. The 2016 summit is to be held again in Washington.

Questions about Russia’s attendance arose after Moscow failed to send a delegation to a preparatory meeting last week. Although the State Department and the White House said Tuesday that they had no information about news reports saying Russia would boycott the summit, U.S. officials said Wednesday that official notification to that effect had been received by the administration prior to last week’s meeting.

In its own statement Wednesday, the Russian Foreign Ministry said it considered leaks about the decision “an unsuccessful attempt to put pressure on the Russian side in order to change our decision.”