Russian Prime Minister Dmitry Medvedev on Thursday appointed former Kremlin foreign policy adviser Sergei Prikhodko as the head of his government's administration following the sudden departure of Deputy Prime Minister Vladislav Surkov.

Prikhodko worked as Medvedev's foreign policy adviser when he served as president between 2008 and last year.

Israel has warned the United States that Russia plans to sell sophisticated missile systems to Syria that would complicate any foreign intervention there, the Wall Street Journal reported.

The Journal reported late Wednesday that Israel had provided information to Washington about the imminent sale to Syria of Russian S-300 missile batteries, advanced ground-to-air weapons that can take out aircraft or guided missiles.

Fighter jets screamed over Red Square and heavy tanks rumbled over its cobblestones Thursday as Russia flexed its military muscle on the anniversary of its costly victory over Nazi Germany in World War II.

The first decision to hold Victory Day parades was taken by Soviet dictator Joseph Stalin himself after the country lost an estimated 27 million people defending its territory and the Eastern Front.

British Prime Minister David Cameron announced on Wednesday he will fly to the Russian resort of Sochi on Friday to discuss the Syrian conflict with President Vladimir Putin.

The trip was confirmed by the Kremlin, which said in a statement that Cameron would be on a "working visit" without giving further details.

Russian President Vladimir Putin on Wednesday dismissed his influential deputy prime minister Vladislav Surkov credited with designing the country's notorious political system.

The Kremlin said in a statement that Surkov had left his post voluntarily, but analysts and observers said the former Kremlin grey cardinal had been forced out amid a growing rift between Putin's Kremlin and the government.

U.S. Secretary of State John Kerry met with Russian rights activists Wednesday as he faced a tough balancing act between trying to find common ground with the Kremlin on Syria and signaling support for the country's embattled civil society.

On his first visit to Russia as the top U.S. diplomat, Kerry conspicuously steered clear of criticizing Moscow in an apparent attempt to soothe months of tensions after President Vladimir Putin's return to the Kremlin for a new term last May.

U.N.-Arab League envoy to Syria Lakhdar Brahimi on Wednesday "warmly welcomed" an agreement between the United States and Russia to pressure both sides in Syria to end the bloodshed, a statement from his office said.

"This is the first hopeful news concerning that unhappy country in a very long time," it said. "The statements made in Moscow constitute a very significant first step forward. It is nevertheless only a first step."

A Russian court on Tuesday sentenced a Chechen man to 15 years in prison for murdering a former Russian colonel, who notoriously strangled to death a young Chechen woman, a spokesman said.

According to investigators, Yusup Temerkhanov killed Yuri Budanov to avenge the death of his father who perished during a "counter-terrorist" operation conducted by Russian forces in Chechnya in 2000.

Russia and the United States agreed at top-level talks on Tuesday to push both the Syrian regime and rebels to find a political solution to their conflict and to hold an international peace conference, the Russian foreign minister said.

"We agreed that Russia and the United States will encourage both the Syria government and opposition groups to find a political solution," Foreign Minister Sergei Lavrov said after talks with U.S. counterpart John Kerry in Moscow.

Regional players, including Hizbullah, are intervening more and more openly in Syria, some emboldened by the chaos created by the conflict, others desperate to prevent the fall of the regime, experts say.

The conflict between President Bashar Assad's government and rebel forces has divided the Middle East, with his allies -- Iran and Hizbullah -- lined up against Gulf states which back the uprising.