Moscow: The top diplomats of Russia and the United States on Friday joined forces to pay tribute to the victims of the Nice attacks but remained divided on how to deal with the war in Syria.
Secretary of State John Kerry and Foreign Minister Sergei Lavrov took a break from their talks to visit the French embassy in Moscow to sign a book of condolences, before returning to their discussions.
A Russian delegation official told reporters that a planned news conference had been postponed for at least two hours while the two sides separated to confer privately.
After observing a minute's silence for the victims ahead of the talks, Kerry stressed the urgency of closer cooperation in Syria after the Kremlin said today a US proposal for direct military cooperation in the war-torn country had not been addressed in earlier talks with President Vladimir Putin.
"Nowhere is there a greater hotbed and incubator for these terrorists than in Syria," Kerry said.
"And I think people all over the world are looking to us and waiting for us to find a faster and more tangible way" to fight terrorism, Kerry said.
"And you and I and your teams are in the enviable position of actually being able to do something about it," he added, addressing Lavrov.
Kerry's meeting with Lavrov -- which had been expected to finish earlier -- follows what the top US diplomat said were "serious and frank" talks with Putin yesterday.
But the Kremlin said today that direct military cooperation between Moscow and Washington in Syria, a proposal Kerry was set to make, had not been addressed in yesterday's talks.
According to a leaked document seen by the Washington Post, Kerry's key proposal is to offer Russia closer US military cooperation against the Al-Nusra Front jihadist group.
In exchange, Moscow would be required to pressure its ally Syrian strongman Bashar al-Assad to ground his own jets and end attacks on civilians and the moderate opposition.
Kremlin spokesman Dmitry Peskov said today that the talks between Putin and Kerry had not marked the start of cooperation "to significantly improve the effectiveness of efforts in the fight against terrorism".
US officials were careful not to call the talks a last chance for diplomacy to resolve the bloody five-year-old conflict, but they warned time was running out.
Washington blames the failure of the peace process on Assad's ceasefire violations and on Al-Nusra's increasing influence among the surviving rebel factions.