A Russian fighter jet flew dangerously close to an American reconnaissance aircraft during an “unprofessional” intercept in international airspace over the Black Sea last month, the Pentagon said Friday.

The American RC-135 was conducting routine operations May 30 when a Russian SU-27 Flanker flew up from behind, passed underneath then crossed over to the American plane’s right-hand side, spokesman Colonel Steve Warren said.

Russia's negotiator said Friday that there has been a "very worrying" slowdown in progress in nuclear talks between Iran and six major powers ahead of a June 30 deadline to finalize an historic accord.

"The rate of progress... is progressively slowing down," Sergei Ryabkov was quoted by RIA Novosti as saying as he arrived for the latest round of talks in Vienna.

The OSCE looks set to name an Austrian diplomat to replace Switzerland's Heidi Tagliavini as the security body's representative in peace talks over Ukraine, diplomats and press reports said Friday.

Envoys at Organization for Security and Co-operation in Europe headquarters in Vienna said that Martin Sajdik, currently Austria's ambassador to the United Nations, was in the frame for the job.

A Russian-American pleaded guilty Thursday to smuggling $65 million worth of electronic components to Russia including parts that ended up in the hands of Moscow's security services and nuclear experts.

Alexander Brazhnikov Jr, 36, a naturalized U.S. citizen born in Moscow, ran an elaborate scheme with the help of his father to illegally transport the components from America to Russia in violation of export control laws, the Department of Justice said. 

Washington's U.N. envoy accuses Russia on Thursday of spinning "outright lies" on Ukraine designed to hide the Kremlin's direct involvement in a war it launched to thwart Kiev's alliance with the West.

Samantha Power delivered an emotional address to a crowd of hundreds in Kiev designed to reassure pro-Western Ukrainians that Washington's backing of its decision to break most post-Soviet ties with Russia and join the European Union remained strong.

Russia on Thursday warned the United States of consequences if it moves to deploy land-based missiles in Europe in contravention of a key Cold-War era arms control treaty.

"It is clear that such actions would mean complete destruction by the American side of the regime of the treaty with all its attendant consequences," the Russian foreign ministry said, referring to the 1987 INF treaty on intermediate-range and shorter-range missiles.

Russia and Egypt are holding their first ever joint naval exercises, the defense ministry said Wednesday, in a bid to strengthen ties amid Moscow's confrontation with the West.

"The active phase of joint Russian-Egyptian naval exercises called The Bridge of Friendship-2015 started today in the Mediterranean Sea near the shores of Egypt," the Russian defense ministry said in a statement.

Vladimir Putin used a trip to Italy on Wednesday to press his case against international sanctions on Russia and insist he was committed to a peaceful resolution of the crisis in Ukraine.

After telling Italian premier Matteo Renzi that sanctions imposed over Russia's actions in Ukraine would cost Italian companies a billion euros, Putin spent 50 minutes chatting to the pope, who presented him an "Angel of peace" medallion.

NATO on Tuesday launched the first full drill of its new spearhead force in northern Poland, a structure designed to boost security on its eastern flank in the wake of Russia's 2014 annexation of Crimea from Ukraine.

Around 2,100 soldiers from nine NATO states grouped in the Very High Readiness Joint Task Force (VJTF) are taking part in the Noble Jump 2 exercises at the Zagan training range north-western Poland.

Russia has opened a criminal probe into the only lawmaker who voted against Moscow's annexation of Crimea, accusing him of embezzlement, authorities announced Tuesday. 

The Investigative Committee, which reports directly to President Vladimir Putin, accused MP Ilya Ponomaryov of complicity in embezzling 22 million rubles ($394,000, 351,000 euros) from the Skolkovo Foundation, a high-tech project that the Kremlin hoped would be its answer to Silicon Valley.