The G7 has ignored calls by the UK and US to impose sanctions against Moscow for its support of Syrian leader Bashar al-Assad.

UK Foreign Secretary Boris Johnson had hoped that foreign ministers would agree to the measures against Syria's chief sponsor, Russia, in the wake of the apparent chemical weapons attack in Khan Sheikhoun.

But UK government sources told the BBC that any sanctions against Russian and Syria will not be happen until there is an investigation and "hard and irrefutable evidence" into the attack that killed 89 people.

The Italian Foreign Minister Angelino Alfano said Russia must not be "pushed into a corner" and that Moscow should pressure Assad to stop the use of chemical weapons, and join the push for peace in Syria.

Ending the G7 ministers meeting in the Italian town of Lucca, he said: "We must have a dialogue with Russia", the Associated Press reported.

He added that there was "no consensus" among the group of the world's biggest industrialised countries for more sanctions against Russia and that isolating Moscow "would be wrong".

Syria denies it carried out a chemical attack which led to the US firing 59 cruise missiles at a Syrian airbase.

US Secretary of State Rex Tillerson said its strike was a question of US national security interest. He said at the end of the G7 meeting: "We do not want the regime's uncontrolled stockpile of chemical weapons to fall into the hands of Isis or other terrorist groups who could and want to attack the United States or our allies.

"Nor can we accept the normalisation of the use of chemical weapons by other actors or countries in Syria, or elsewhere."

Tillerson will go to Moscow later on Tuesday (11 April) to discuss Russia's links with Syria.

Italy's Foreign Minister Angelino Alfano told a news conference at the end of a G7 for foreign ministers in Lucca that Russia must 'not be pushed into a corner' over Syria and rejected British calls for sanctions against Moscow. Reuters