President Vladimir Putin is expected Tuesday to host U.S. Secretary of State John Kerry for crucial talks in Sochi amid tensions over Ukraine, during the top U.S. diplomat's first visit to Russia since the start of the crisis.

Ties between Moscow and Washington collapsed after Russia seized Crimea and buttressed separatists in eastern Ukraine but after a year of raging tensions signs are emerging that both Russia and the West may be ready to seek detente.

Head of al-Mustaqbal Movement and former Prime Minister Saad Hariri will head to Moscow for a two-day official visit this week to tackle the crisis gripping Lebanon, at forefront the presidential vacuum.

Local newspapers reported on Monday that Hariri will meet during his visit to Russia President Vladimir Putin, Foreign Minister Sergei Lavrov and other senior officials.

Russian President Vladimir Putin on Sunday defended the infamous pact between Nazi Germany and the Soviet Union that agreed to divide up eastern Europe during a visit by German Chancellor Angela Merkel.

On August 23, 1939, Germany and the Soviet Union agreed to carve up eastern Europe between them in a secret clause of the Molotov-Ribbentrop Pact on non-aggression.

German Chancellor Angela Merkel on Sunday paid tribute to Soviet soldiers killed in WWII as she called for cooperation with Russia amid tensions over Ukraine.

Merkel flew to Moscow to lay a wreath at the grave of the Unknown Soldier near the Kremlin walls, in an apparent compromise gesture after she skipped Russia's main festivities on Saturday.

President Vladimir Putin on Friday congratulated "citizens" of Ukraine but snubbed its leaders on the 70th anniversary of Soviet victory over Nazi Germany in WWII amid a deep feud between Moscow and Kiev. 

Putin pointedly sidestepped addressing Ukraine's pro-Western authorities as he issued a congratulatory statement to the governments of other former Soviet republics that fought alongside Moscow in WWII. 

China's Xi Jinping flew into Moscow Friday as some two dozen world leaders headed to Russia for a grandiose World War II victory parade that has been snubbed by the West.

Russia will roll out its military might at the Red Square parade to mark 70 years since victory over Nazi Germany from 10:00 am on Saturday (0700 GMT) with 16,000 troops and a display of hardware including the latest generation Armata tanks.

Head of al-Mustaqbal Movement and former Prime Minister Saad Hariri met on Tuesday with French President Francois Hollande in Riyadh.

The meeting comes in light of Hariri's shuttle diplomacy to safeguard Lebanon from the conflict raging in the region.

The Ukrainian presidency on Thursday said Russian President Vladimir Putin was open to the deployment of a peacekeeping mission in war-torn eastern Ukraine, after the leaders of both countries spoke by phone with their French and German counterparts.

"In the context of the discussion of ways towards a peaceful resolution (of the conflict), President Putin has accepted the possibility of deploying a peacekeeping contingent to the Donbass region," the presidency said in a statement.

Lithuanian border guards said Tuesday they had denied entry to eight Russian bikers including at least one member of a pro-Kremlin group attempting that had planned a controversial WWII victory ride through Europe.

The border guard service said it turned away eight Russian citizens at the Baltic state's borders with Belarus and the Russian enclave of Kaliningrad on Monday and Tuesday.

Ten pro-Kremlin bikers on a controversial ride to Berlin to celebrate Soviet victory in World War II were on Monday denied entry into Poland at the Belarusian border, Polish border guards said. 

The bikers include members of the Night Wolves, a fiercely nationalist club closely linked to Russian President Vladimir Putin.