Russia may be trying to place themselves in a position to turn a weakening government towards making alliances with opposition members that the Russian government supports, effectively molding the political developments of the country in their favor.

State Department spokesman Mark Toner echoed Earnest’s message, saying “we have seen various reports that Russian Federation may be deploying military personnel… we’re unclear what these might be used for”.

Social media accounts close to Syrian militant, Al-Qaeda affiliated group the Al-Nusra Front also posted images of what they purported to be a Russian Su-34 fighter in flight over Syria.

Given Putin’s track record of denying Russia’s military involvement in Ukraine, US officials say they are not putting much stock in his public statements about Syria.

Meanwhile, officials in Washington have expressed concern over unverified reports of increasing Russian military support to Assad’s forces, including possible troop deployments.

While the USA, the European Union and the Persian Gulf nations have sided with Syrian rebels and opposition since unrest in the country began in 2011, Russian Federation – a staunch supporter of the Syrian government since the Soviet era – has refused to do so, opposing demands calling for Assad’s ouster. Russian Federation has been a long-time ally of the Assad regime. The Times of London reported Thursday that video shot by a militia loyal to Assad and aired on SANA, Syria’s state-run television station, showed troops backed by an armored vehicle.

But Mr Putin’s comments chime with experts who say the Russian government would be willing to supply substantial logistical support and advice even if it shies away from large-scale intervention.

Putin also said the European migrant crisis was prompted by the atrocities of the Islamic State jihadist group, not by Assad. The US, which leads an anti-ISIS coalition, has been carrying out airstrikes on ISIS targets in Syria since last September, helping the so-called moderate Syrian rebels advance against the group.

“It is too early” to talk about Russian military action in Syria, though “we are considering various options”, Putin said.

Last month, the head of the opposition Syrian National Coalition said after a meeting in Moscow with Foreign Minister Sergei Lavrov that the “Russian leadership isn’t clinging to Bashar Assad”.

“Such things are kept very secret, but there is definitely an adviser and instructor mission there, possibly numbering in the hundreds”, said Pavel Felgenhaeur, an independent commentator on Russian military affairs.