Putin defends Assad regime and suggests its enemies had concocted evidence it was behind chemical attack

Ahead of Mr Tillerson’s arrival in Moscow on Tuesday evening, Mr Putin brushed aside claims that Damascus was behind last week’s chemical attack, which killed 89 people, including children.

He claimed Moscow had intelligence “from different sources” that it was carried out by rebel groups, which were trying to draw the US deeper into the conflict.

“We have information that a similar provocation is being prepared in other parts of Syria, including in the southern Damascus suburbs, where they are planning to again plant some substance and accuse the Syrian authorities of using chemical weapons.”

The Russian President suggested the allegations against Assad were similar to the now-discredited claims that Saddam Hussein had stockpiled weapons of mass destruction in Iraq.

“It reminds me of the events in 2003,” declared Mr Putin, “when US envoys to the Security Council were demonstrating what they said were chemical weapons found in Iraq. We have seen it all before.”

The Russian leader’s remarks came as Turkey said test results on victims confirmed sarin gas was used in the attack on the rebel-held town of Khan Sheikhoun in northern Syria.

The results were announced as the Russian military said the Syrian government was willing to let international experts examine its military base for signs of chemical weapons and as Mr Putin said Moscow would appeal to the United Nations to investigate the chemical weapons strike.

In New York, the French Government made clear that it would be pressing again for a UN Security Council resolution condemning the chemical attack in Syria and calling for a thorough investigation so the world knew how it had occurred and who was responsible.

Earlier, following a meeting of G7 foreign ministers in the Tuscan city of Lucca, Boris Johnson said there was now an opportunity for Mr Putin to "reset" relations with the West and to join the US-led coalition against so-called Islamic State.

"They have a big strategic choice. Do they want to stick with this guy who is poisoning his own people and poisoning the reputation of Russia or do they want to be part of the solution?" the Foreign Secretary told Sky News.

"Of course, everybody understands that Russia has political and strategic interests in Syria; all that can be respected. But at the same time, Russia needs an exit from this disaster in Syria.

"What we all want to see is Russia engaging with a political process that involves a transition to a new government in Syria. That is the offer Rex Tillerson is going to be making."

Yet there was no agreement among the G7 ministers on a call by Mr Johnson for targeted sanctions against senior Russian and Syrian military figures implicated in last week's chemical weapons attack.

Angelino Alfano, the Italian foreign minister, insisted: "We must have a dialogue with Russia and we must not push Russia into a corner. There is no consensus on additional new sanctions as an efficient instrument to deliver the goal we are aiming for."

Meantime, the White House made clear that it could mount further strikes against the Assad regime if there were any fresh use of chemical weapons, despite a threat of retaliation from Russia and Iran.

Sean Spicer, Donald Trump’s spokesman, said: "When you watch babies and children being gassed and suffer under barrel bombs, you are instantaneously moved to action.

"This president has made it very clear that if those actions were to continue, further action will definitely be considered by the United States."

Mr Tillerson is due to meet his Russian counterpart, Sergey Lavrov, but it is not yet decided whether or not he will have a meeting with Mr Putin.