Putin warns of chemical weapons 'provocations' to frame Assad

Putin was speaking hours before US Secretary of State Rex Tillerson was due to arrive in Moscow for talks with Russia's foreign minister and days after denouncing last week's US missile strike on a Syrian air base as illegal.

On Sunday, Tillerson said he was "hopeful" that the USA could work with Russian Federation to "achieve areas of stabilization throughout Syria" and move toward a political solution to the six-year-old conflict.

The Russian Foreign Ministry said it does not expect much from the meeting, but having the opportunity to discuss pressing worldwide issues is a positive step.

Until Monday, US officials had said they weren't sure if the drone had been operated by Russian Federation or Syria.

Mr Tillerson said the aim was to deliver stability and ensure that the Syrian people have a say in their own future.

The top USA diplomat carries an ultimatum for his host: either side with world powers in seeking an end to the Syrian war, or continue the alliance with Iran and the militant group Hezbollah in supporting the Assad regime.

US President Donald Trump and British Prime Minister Theresa May have agreed that a "window of opportunity" exists to convince Russian Federation to end its support for Syrian President Bashar al-Assad.

The U.S. received broad support from Europe after the airstrikes.

"It is unclear whether Russian Federation failed to take this obligation seriously or Russian Federation has been simply incompetent in its ability to deliver on its end of that agreement", he said.

"That's why we are not presupposing how that occurs", Tillerson added. "Or Russia can maintain its alliance" with Syria and Iran. The resulting political talks would take place under the auspices of the United Nations process in Geneva.

"To date, Astana has not achieved much progress", Tillerson said.

Tillerson met in Italy on Monday with members of the Group of Seven leading nations - the U.S., U.K., France, Germany, Canada, Japan and Italy.

At the press conference after the meeting, Italian Foreign Minister Angelino Alfano described the USA intervention as a window of opportunity.

But Alfano said there was "no consensus" among the G7 countries. Moscow is a staunch ally of President al-Assad, whom the United States blamed for the chemical attack.

"It reminds me of the events in 2003 when USA envoys to the Security Council were demonstrating what they said were chemical weapons found in Iraq", Putin told reporters on Tuesday.

He said the United Nations should first investigate the attack. Why would Assad jeopardize a status quo in which the US was reconciling itself to his regime's survival by killing his people with the one kind of weapon that had previously led America to the brink of intervention?

That accusation will hang over Tillerson's visit to Moscow, where he plans with meet with Russia's foreign minister, Sergey Lavrov, and possibly with Russian President Vladimir Putin.

Tillerson met with Putin several times when he was the CEO of oil giant Exxon, a role he relinquished in order to join the Trump administration.

Diplomatic relations between Russia and the United States are the most hard they have been since the end of the Cold War, the Russian foreign ministry has said.

As Tillerson landed in Moscow, senior White House officials briefed reporters on declassified US intelligence they said disproved Russia's claim that rebels were responsible for the chemical weapons.

The group's stance was a rebuff to British Foreign Secretary Boris Johnson, who said Monday the G-7 was considering new sanctions on Russian military figures to press Moscow to end military support for the "toxic" Assad government.

Russian Federation is already under a raft of sanctions imposed by the United States and European Union in response to the annexation of Crimea and the crisis in eastern Ukraine.

The U.S. has been focusing its military action in Syria on defeating the Islamic State group.