US President Donald Trump has tweeted that Russia should "prepare" for rockets to be let go at its partner Syria, in light of a charged synthetic assault close Damascus on Saturday.
"Prepare Russia, since they will come, decent and new and 'shrewd!'" Mr Trump said in his tweet.
Senior Russian figures have undermined to meet any US hits with a reaction.
President Bashar al-Assad's administration denies mounting a synthetic assault on the agitator held town of Douma.
In one his tweets on Wednesday, Mr Trump called the Syrian leader a "gas killing creature". In another, he painted a dark picture of US-Russia relations however said it didn't need to be that way.
The US, UK and France have consented to cooperate and are accepted to get ready for a military strike.