Donald Trump has blamed Iran for supporting and aiding "unspeakable crimes" in Syria under its leader Bashar al-Assad. Mr Trump, during his speech on combating violent extremism in Saudi Arabia, did not mention Syria's alliance with Russia to carry out air strikes. Near the end of his speech in Riyadh about forging peace, he argued that Iran had provided Syria with "safe harbour, financial backing and the social standing needed for recruitment [of terrorists]".