The European Union has been using all diplomatic channels to convince US President Donald Trump to stick with the Iran nuclear deal. With Trump deciding to go against the EU's pleas and withdraw his country from the agreement, EU-US relations might be coming to a breaking point.
At last year's conference, participants pledged 6 billion dollars for 2017. The EU hopes to surpass that figure at this year's conference.
European leaders discuss Brexit, the nerve gas attack in Britain and proposed US tariffs during a two-day summit in Brussels.