Theresa May and Donald Trump discussed the crisis in Syria on Monday following America’s military strikes against the Syrian government last week.
Boris Johnson has reiterated the message Russia needs to back away from their relationship with Syrian leader Bashar al-Assad.
Speaking to Newsnight the Foreign Secretary issued an appeal for the Russian President to abandon his backing for Assad.
He said: “The message that we are sending to the Russians is very very clear.
Boris Johnson issued a grave warning to Vladimir Putin
“Do they want to stick with a toxic regime?
“Do they want to be eternally associated with a guy who gases his own people?
“Or do they want to work with the Americans, and the rest of the G7, and indeed the likeminded countries?”
It is believed Russia may be encouraged to withdraw from Syria with the prospect of being able to rejoin the G7, which is thought to be desired by Putin after he was suspended from the group in 2014.
President Trump launched missiles at an air base in Syria last week which was in response to the suspected chemical weapons attack in Syria which killed at least 86 people.
Do they want to be eternally associated with a guy who gases his own people
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The UK Defence Secretary, Sir Michaeal Fallon said the Government fully supported the President’s actions, however Mrs May has refused to support further attacks.
Mr Johnson cancelled his Moscow summit after being due to meet Sergei Lavrov to discuss British concern over Putin’s support for Assad.
During a G7 meeting on Monday, the Foreign Secretary suggested that senior Russian military officers could face international sanctions if they were seen to be in support of Assad’s campaign.
Mr Johnson added President Trump’s actions had “changed the game” and the Russians had to decide which side they were on.
Countries that support and oppose the missile strikes in Syria Mon, April 10, 2017
European countries have been broadly supportive so far as President Trump ordered missile strikes against a Syrian airfield from which a deadly chemical weapons attack was launched
AFP/Getty Images 1 of 7
SYRIA OPPOSES: President Bashar al-Assad's office denounced the U.S. strike as 'reckless, irresponsible behavior.'
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 co-ordinating the Syrian military efforts.”
President Trump thanked the Prime Minister on Monday for her backing of the military strikes in Syria.
A Downing Street spokesman said: “The President thanked the Prime Minister for her support in the wake of last week's US military action against the Assad regime.
“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.”