Russia faces being hit with new international sanctions amid soaring tensions in the wake of the deadly chemical weapons attack in Syria.

Spearheading a drive to gather support for the move at the G7 meeting in Tuscany, Foreign Secretary Boris Johnson said Vladimir Putin and his allies had a choice of either backing the “toxic regime” of Bashar al-Assad or helping the world end Syria’s bloody six-year conflict.

Mr Johnson said sanctions could target key Russian and Syrian military figures who have assisted the Assad regime, mirroring punitive measures put in place following Mr Putin's annexation of Crimea in 2014.

But as news of the potential punishment for Moscow emerged, Russian diplomatic insiders sought to drive a wedge between the US and UK, claiming that the situation was “too serious to spend too much time on Boris” and that they would wait to hear what the Americans came forward with.

Sources close to the Foreign Secretary told The Independent he would gauge support for sanctions at a working G7 dinner, with the goal of convincing allies to commit to a joint position on action which can then be put to Mr Putin by US Secretary of State Rex Tillerson later this week.

Arriving at the summit, Mr Johnson said US President Donald Trump's decision to launch 59 Tomahawk cruise missiles against the Syrian airbase believed to be the source of the Idlib chemical weapons attack had “changed the game”, creating a platform from which the West could lever new concessions from Moscow.

But the new diplomatic push comes amid threats of further military action in Syria from the US, Russia and Iran, which also has forces in play backing the Assad regime.

The first thing Mr Johnson did on reaching the G7 summit venue was head into an hour-long bilateral meeting with Mr Tillerson, with whose team the UK Government has been in close contact since Mr Trump launched US missiles at the Shayrat airfield.

Setting out his position towards Russia on the way in, Mr Johnson said: “They have a choice. That choice is to stick like glue to the Assad regime – that toxic regime which poisons its own people and is indeed poisoning the reputation of Russia – or to work with the rest of world to find a political solution.”

In pictures: US missile strike against Syria Show all 7 1 /7 In pictures: US missile strike against Syria In pictures: US missile strike against Syria The guided-missile destroyer USS Porter (DDG 78) launches a tomahawk land attack missile in the Mediterranean Sea AP In pictures: US missile strike against Syria The United States military launched at least 50 tomahawk cruise missiles at al-Shayrat military airfield near Homs, Syria, in response to the Syrian military's alleged use of chemical weapons in an airstrike in a rebel held area in Idlib province EPA In pictures: US missile strike against Syria Shayrat airfield in Syria Getty Images In pictures: US missile strike against Syria US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters In pictures: US missile strike against Syria US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters In pictures: US missile strike against Syria President Donald Trump speaks at Mar-a-Lago in Palm Beach, Fla., after the US fired a barrage of cruise missiles into Syria in retaliation for this week's gruesome chemical weapons attack against civilians AP In pictures: US missile strike against Syria Syria's President Bashar al-Assad Reuters

With other foreign diplomats still arriving in Lucca, he said: “We will be discussing the possibility of further sanctions, certainly on some of the Syrian military figures and indeed on some of the Russian military figures, who have been involved in coordinating the Syrian military efforts and are thereby contaminated by the appalling behaviour of the Assad regime.

“It is the Americans who have changed the game by using those cruise missiles which never happened in the last five years, so the game has now been changed and I think it’s important that that message should be heard from the Americans to the Russians.”

It is the first serious talk of new sanctions on Russia since the US and EU instigated a series of measures on individuals and organisations that they saw as playing a part in the 2014 annexation of Crimea.

Those measures put in place a range of financial sanctions against Russian defence companies, big energy and oil exploration firms, asset freezes and travel restrictions on individuals linked to the annexation and also the suspension of credit finance for Russian exports and financing for Russian development projects.

The measures are believed to have had a significant impact on the Russian economy and the country’s GDP growth, with Russian diplomats lobbying for them to be removed, though they appear not to have dissuaded Mr Putin from acting in Crimea.

Sources close to the Foreign Secretary said the UK and US were in complete agreement that the entire Assad family had no role “leading the country to its future”.

Mr Johnson has undertaken the new push for sanctions amid criticism that he is playing second fiddle to the US, in particular after he cancelled a trip to Moscow to allow Mr Tillerson to take a single united message over Syria to Mr Putin from the West – a decision heavily criticised by the Russian president’s officials.

One Russian diplomatic source told The Independent: “Our position is that there is not only no evidence of Russian involvement, there is also no evidence that the Syrian government carried out a chemical attack either.

“That is the reason we have asked for a thorough and impartial international investigation into what happened. There is no reason why the Americans should object to an investigation if they want the truth to come out.

“But we need to see what the G7 and the Americans have to say instead of spending too much time on what Boris is saying. The situation is too serious to spend too much time on Boris. He is a foreign minister who seems to have no control over his own diplomatic visits and has to cancel agreed visits on orders of others.

“Embarrassing no? But Mr Tillerson is coming to Moscow. It will be better to have a meeting among equals.”

Mr Trump’s decision to launch missiles at the airbase in Syria’s Homs province, believed to be the source of the chemical attack that killed scores of people and injured many others, saw Russia and Iran threaten military action if the US crossed red lines in Syria.

US Defence Secretary Jim Mattis said last night that the strike had damaged or destroyed 20 per cent of Syria's operational aircraft, as well as fuel and ammunition sites and air defence capabilities.

“The Syrian government has lost the ability to refuel or re-arm aircraft at Shayrat airfield and at this point, use of the runway is of idle military interest,” he said.

“The Syrian government would be ill-advised ever again to use chemical weapons.”

Downing Street on Monday reiterated the Government's support for the strike while calling for a renewed diplomatic push to end Syria's civil war.

But Prime Minister Theresa May's official spokesman refused to be drawn on whether the UK would support further US military action, saying it was a “hypothetical question”.

There was outrage across the world after dozens of civilians were killed in what is believed by the West to have been a chemical weapons attack on the Syrian village of Khan Sheikhoun by the Assad regime.

Anticipating tough language from the G7 in Italy, Russia and Iran issued on Monday a joint call for an “unbiased investigation” into the gassing at the Syrian village.