Misfit
Lawful neutral
http://www.bbc.com/news/world-middle-east-43727829
"Get ready Russia, because they will be coming, nice and new and 'smart!'" Mr Trump said in his tweet.
Senior Russian figures have threatened to meet any US strikes with a response.
President Bashar al-Assad's government denies mounting a chemical attack on the rebel-held town of Douma.
In one his tweets on Wednesday, Mr Trump called the Syrian leader a "gas killing animal".