Foreign ministers from the Group of Seven (G7) major industrialised nations meeting in Lucca in Italy are looking to put pressure on Russia to break its ties with Syrian President Bashar al-Assad.
Calling last week's US missile strike on a Syrian airbase a "game changer", Boris Johnson, UK foreign minister, suggested that sanctions could be imposed on Russia if it refused to change course.
Italy has invited the foreign ministers from Turkey, Saudi Arabia, United Arab Emirates, Jordan and Qatar to sit down with the G7 group in Lucca on Tuesday to discuss Syria. All oppose Assad's rule.
Rex Tillerson, US Secretary of State, is due to travel to Moscow on Tuesday with his Italian, German, French, British, Japanese and Canadian counterparts.
Johnson said he was keen to see further sanctions imposed on both Syrian and Russian "military figures".
The diplomatic developments come after a suspected chemical attack on a rebel-held Syrian town that the Syrian Observatory for Human Rights, the UK-based monitoring network, said killed 87 people.
It prompted the US to intervene for the first time directly against the Assad government which it has blamed for the attack.
The Syrian government has denied it was behind the April 4 attack in the town of Khan Sheikhoun.
Russia has also rejected the accusations that Assad used chemical arms against his own people while stating that it will not cut its ties with Assad, who has been locked in a six-year-old civil war that has devastated Syria and displaced half its population.
For their part, Theresa May, UK prime minister, and US President Donald Trump agreed in a phone call on Monday that a "window of opportunity" exists to convince Russia to end its support for the Syrian president.
"The prime minister and the president agreed that a window of opportunity now exists in which to persuade Russia that its alliance with Assad is no longer in its strategic interest," a spokeswoman for May's Downing Street office said.
In their phone call, Trump and May said Tillerson's Moscow visit "provides an opportunity to make progress towards a solution which will deliver a lasting political settlement".
Also on Monday, Justin Trudeau, Canada's prime minister, said in France that his country is ready to stiffen sanctions on Russia.
Darul Ihsan Media Desk