U.S. Secretary of State John Kerry met President Vladimir Putin on Tuesday to probe Russia's willingness to curb its involvement in Ukraine and its backing of Syria's president.
Kerry met Russian Foreign Minister Sergei Lavrov for more than four hours before he sat down with Putin in the Black Sea resort of Sochi in what was the highest-level U.S. visit to Russia since the Ukraine crisis began in the autumn of 2013.
While they were expected to discuss issues including the Iran nuclear talks, Yemen and Libya, the trip appeared designed as much to maintain contact as anything else given that U.S.-Russian relations are at their lowest ebb since the Cold War.
"It's important for us to keep these lines of communication open. It's important to try to talk to the senior decision-maker," said a senior U.S. State Department official who briefed reporters as Kerry travelled to Russia.
"We have a lot of business that we could do together if there is interest," said the official, who spoke on condition of anonymity.
Putin's spokesman, Dmitry Peskov, welcomed the meeting as a positive step.
"Through dialogue, it is possible to find ways for a normalisation, closer coordination in dealing with international problems," Peskov told reporters before the talks began.
But he added: "Russia was never the initiator of this cooling of relations."
Ties between Washington and Moscow have deteriorated since Russia annexed Ukraine's Crimea Peninsula in March 2014 and backed pro-Russian separatist rebels in eastern Ukraine. Moscow accuses Washington of orchestrating last year's overthrow of a Ukrainian president who was supported by Russia.
The United States has accused Russia of failing to withdraw heavy equipment such as air defence systems, tanks and artillery from eastern Ukraine in violation of a peace plan agreed in February and known as Minsk 2.
Russia denies Western and Ukrainian accusations that it is arming the pro-Russian separatists battling the government and supporting them with its own military forces. More than 6,100 people have been killed since April 2014 in the Ukraine crisis.
The United States and European Union imposed economic sanctions on Russia after it took over Crimea and have intensified them since. The U.S. official hinted they could be eased if Russia complied with the Minsk plan, which calls for withdrawing heavy weaponry and respecting Ukraine's border.
Washington and Moscow are also at odds over the civil war in Syria, where Russia has backed Syrian President Bashar al-Assad while the United States wants a political transition to end his family's 45-year-old rule.
While there have been no outward signs of a Russian reversal on Ukraine or Syria, U.S. officials hope recent defeats to Assad's forces may change the Russian stance.
Insurgents overran the northwestern Syrian town of Jisr al Shughour last month and the provincial city of Idlib a month earlier, both in the rich agricultural province of Idlib.
The senior U.S. official also said it was important to meet Putin to discuss the Iran nuclear talks, which aim to reach an agreement by June 30 under which Tehran would curb its atomic programme in exchange for the easing of economic sanctions.