U.S State Secretary John Kerry has arrived in Moscow to meet with President Putin

U.S. Secretary of State John Kerry arrived in Moscow Tuesday for talks with Russian President Vladimir Putin, seeking to restore frayed U.S.-Russia ties and win Moscow's support on the war in Syria.

Kerry is making his first trip to Russia since taking over as the chief U.S. diplomat in February, on what is one of his most diplomatically delicate missions to date.

The visit coincides with the first anniversary of Putin's return to the Kremlin for a historic third term on May 7, 2012 which heralded a new chill in relations between Moscow and Washington.

Syria is likely to top the agenda when the two men meet later Tuesday with the 26-month war threatening to spill across the region. Later, Kerry will also meet Foreign Minister Sergei Lavrov.

Washington has long urged Moscow -- Syrian President Bashar Assad's most powerful ally -- to use its sway to halt the bloodshed, accusing Russian leaders of continuing to arm the Syrian regime.

And while Moscow has insisted on the need for a political solution to the fighting it has grown increasingly alarmed by the war. The foreign ministry said it was "especially" concerned by Israeli strikes on Syrian targets, warning the violence threatens Lebanon.

There are a host of other issues on the agenda of the talks, including last month's Boston marathon bombings blamed on two brothers of Chechen descent.

More contentious dossiers include American missile defense, and rows over a ban by Moscow on American adoptions of Russian children and the Russian authorities' harassment of NGOs.