The Russian Embassy in London has described Boris Johnson's decision to cancel his planned visit to Moscow in light of the country's defence of the Syrian President Bashar al-Assad as "deplorable".
The Foreign Secretary was due to visit Russia on Monday for talks with counterpart Sergey Lavrov.
But on Saturday Mr Johnson announced he would not be travelling to Moscow, saying: "we deplore Russia's continued defence of the Assad regime".
In a tweet on Sunday morning, the Russian embassy said: "It is deplorable that Boris Johnson found himself unfit to stand Western ground on Syria in bilateral talks with Sergey Lavrov".
Boris Johnson looks "daft" and is in "deep political trouble" after pulling out of a meeting with the Russians, Alex Salmond has said.
The defence secretary condemned Vladimir Putin's Kremlin for its role in Bashar Assad's suspected chemical weapons attack on his own people.
The leading critic of the Trump administration has told ITV News the US and its allies must build on the president's justified airstrikes.