Boris Johnson has cancelled his planned visit to Moscow
The former Mayor of London was due to fly out to meet Russian counterpart Sergei Lavrov on Monday.
But after US President Donald Trump launched 59 tomahawk missiles on a Syrian airbase in Homs, a response to Tuesday's chemical attack in Khan Sheikhoun, the talks have been cancelled.
The foreign secretary said recent events in Syria had "changed the situation fundementally" and that he would now prioritise talks with the G7 nations over the ongoing crisis.
"I will now not travel to Moscow on Monday 10 April," Mr Johnson said.
"My priority is now to continue contact with the US and others in the run up to the G7 meeting on 10-11 April – to build coordinated international support for a ceasefire on the ground and an intensified political proccess."
However, Liberal Democrat leader Tim Farron blasted the Foreign Secretary as a "poodle of Washington".
He said: "Our Government quick to blindly follow every order from the Trump White House.
"Boris has revealed himself to be a poodle of Washington, having his diary managed from across the pond.
"It's pretty shameful when even Trump judges you to be a buffoon."
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It was previously believed Mr Johnson would only travel to Russia if Rex Tillerson, the US Secretary of State, decided to go ahead with his own visit, planned for Tuesday.
But Mr Johnson said he discussed the plans "in detail" with Mr Tillerson, and the secretary would still be making the journey as planned, to deliver "a clear and co-ordinated message to the Russians".
"We deplore Russia's continued defence of the Assad regime even after the chemical weapons attack on innocent civilians," Mr Johnson continued.
"We call on Russia to do everything possible to bring about a political settlement in Syria and work with the rest of the international community to ensure that the shocking events of the last week are never repeated."
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Trump's surprise military intervention on Friday has put the US on a collision course with Russia, who have warned the attack on the Shayrat air base could have "extremely serious" consequences.
The Kremlin has repeatedly maintained the gas attack was an accident – the result of Rusian-backed Syrian forced hitting a rebel-held depot that was building chemical weapons.
But the Pentagon released a map hours after the missile strike showing what it claims was the flight path of a Syrian aircraft flying over Khan Sheikhoun on the day of the chemical attack.
The President's decision won him praise from some of his most prominent detractors – including senator John McCain, who said he had "confronted a pivotal moment in Syria and took action".
He was also lauded for making the sort of decisive move in Syria his predeccessor Barack Obama never did.
But by wading into the war in Syria, Mr Trump has alienated some of his most fervant, hard right supporters.