President Donald Trump's national security adviser said on Monday the United States, Britain and France had agreed that another use of chemical weapons by the Syrian government would result in a "much stronger response" compared to previous air strikes. Source: [url=http://feeds.reuters.com/~r/Reuters/worldNews/~3/bfdQ_EsZ7ns/trump-adviser-warns-of-tougher-response-if-syria-uses-chemical-weapons-again-idUSKCN1LQ28F]Trump adviser warns of tougher response if Syria uses chemical weapons again[/url]