Relations between Russia and the US have been at a low ebb during US President Donald Trump's time in office. The ties have been marred by an investigation into alleged Russian interference in the 2016 US presidential election. There was also what some call a media war between the two countries. Meanwhile, in Syria, Russia is Syrian President Bashar al-Assad's main ally, while the US supports the main opposition alliance.  In Ukraine, Russia is furious over the US decision to sell weapons to the government, while Washington accuses Moscow of military intervention in the country.