The UK is in talks with international partners to collectively impose new sanctions on Russia if it does not withdraw support for Syrian President Bashar al-Assad, a government spokesman said.
"We are in discussions with our key partners on how we can bring further pressure to bear on the regime and those who are backing it, which includes the Russians," the spokesman told reporters on Monday.
He also said that Prime Minister Theresa May spoke with her Canadian counterpart, Justin Trudeau, on Sunday and the two leaders agreed to push for a political solution to the Syrian conflict.
The comments come as foreign ministers from the Group of Seven major industrialized countries gathered in Lucca, Italy, on Monday for a summit which is expected to be overshadowed by last week’s suspected chemical attack in Syria, Russia’s support for Assad, and the US missile attacks on a Syrian airbase.
The meeting in Lucca brings together foreign ministers from the US, Britain, Canada, France, Germany, Italy and Japan.
British Foreign Secretary Boris Johnson will press the G7 nations to draw up “very punitive sanctions” in response to last week’s chemical attack in Syria, which the West has pinned on the Syrian government.
The Syrian government has strongly denied responsibility for the attack in Idlib, which left more than 80 people dead. Russia said the chemical explosion was caused by a Syrian airstrike on a militant-controlled depot.
Johnson has cancelled a trip to Moscow to participate in the talks with his “G7 counterparts about Syria and Russia’s support for Assad.”
A paper on sanctions has been prepared for the meeting in Lucca.
In an interview with The Sun, Johnson said US President Donald Trump delivered “a clear and united message” when he ordered the launch of 59 cruise missiles against al-Shayrat airfield, where the West alleges the gas attack originated.
Russia said the military action crossed a “red line” and threatened that it would “respond with force” if there were more strikes in Syria.
The Russian Embassy in London also warned in a tweet that a G7 "ultimatum" to Moscow to cut ties with the Syrian government could result in a “real war.”
US Secretary of State Rex Tillerson, who is due to travel to Moscow on Tuesday, has also pledged to deliver a “clear and coordinated message” when he meets with his Russian counterpart, Sergei Lavrov.
Tillerson said over the weekend that Russia had “failed in their commitment to the international community” by not stopping the chemical attack in Idlib.
The US and EU have already imposed a series of sanctions on Russian individuals and businesses.