British Prime Minister David Cameron and Russian President Vladimir Putin on Friday sought to forge a joint approach to the crisis in Syria, as a row over Moscow's weapons deliveries to Damascus showed up the divisions between the Kremlin and the West.
Cameron's rare call on Putin at his summer vacation residence in the Black Sea resort of Sochi came three days after top US and Russian diplomats agreed to make a joint effort in search of a solution.
But in Warsaw, Foreign Minister Sergei Lavrov confirmed that Russia was continuing to fulfil contracts by delivering military hardware to Bashar al-Assad's regime in defiance of calls for a freeze.
The West and Russia have been repeatedly at odds over the Syria conflict, with the United States and Europe accusing Moscow of seeking to prop up President Bashar al-Assad and selling him arms.
In cordial comments amid the tropical shrubbery of the garden at his Black Sea residence, Putin said he and Cameron had discussed possible options and joint measures for finding peace in Syria.
However there was no sign of an immediate breakthrough, despite the warm tone that was a contrast to the tensions that have bedevilled relations between London and Moscow for years.
"At the initiative of the prime minister, we spoke about the possible options for a positive development of the situation and about practical steps in this regards," Putin said after the talks, according to a Kremlin transcript.
"We have a joint interest in a swift halt to the violence and the creation of the process for a peaceful solution that keeps Syria's territorial integrity and sovereignty," said Putin.
Cameron said it was "no secret" that Russia and Britain had different positions on the Syria conflict but said they shared an ultimate aim of halting the conflict, allowing the Syrian people to elect a government and preventing a growth in extremism.
"Of course, it is no secret that there are issues where we differ. We don't duck these, we have had very frank discussions, as we have today," said Cameron.
Cameron flew to Putin's palm-dotted residence before the British premier's planned meeting with US President Barack Obama at the White House on Monday.
The meeting also allowed Russia and Britain to coordinate positions ahead of the next Group of Eight summit which Cameron is hosting at Lough Erne in Northern Ireland on June 17-18.
The war in Syria has cost an estimated 70,000 lives and displaced millions of people, including hundreds of thousands who have fled to neighbouring countries.
The talks with Putin came amid concerns that Russia may be preparing to hand over to Syria sophisticated surface-to-air missiles which will significantly strengthen its defences and complicate any foreign intervention.
US Secretary of State John Kerry warned that any such sale would be "potentially destabilising" for the region.
Lavrov, on a visit to Warsaw on Friday, defiantly refused to rule out delivering weapons to Syria by completing the implementation of existing contracts.
"Russia is not planning to sell -- Russia has sold and signed contracts a long time ago, and is completing supplies of the equipment -- which is anti-aircraft systems -- according to the already signed contracts," he told reporters.
But German Foreign Minister Guido Westerwelle, speaking at the same news conference, insisted that "international arms deliveries to Syria must end."
Earlier this week, Lavrov and Kerry in a rare joint initiative over the conflict offered to hold an international conference in search of peace in Syria.
UN-Arab League envoy on the Syria crisis Lakhdar Brahimi hailed the initiative which he said had convinced him to stay on in his job which many see as a hopeless mission.
The peace conference proposed by Lavrov and Kerry will aim to build on the unimplemented Geneva accord agreed by world powers last June. The deal set out a path toward a transitional government without spelling out what Assad's fate should be.
Meanwhile, Turkey's staunchly anti-Assad Prime Minister Recep Tayyip Erdogan said he believed the Syrian regime has used chemical weapons, crossing a "red line" set out by Obama.
"We want the United States to assume more responsibilities and take further steps," Erdogan, who will meet Obama on May 16, told NBC news.