It's essentially a high-level public relations exercise that risks falling humiliatingly flat.
In the heat of the EU upset following Britain's June vote to leave, it probably seemed very sensible to get the other 27 EU countries round a table - after a cooling-off period - to discuss the "what next".
Also read: Trump brings his solo act to Europe
04:13 Trump to meet with anxious NATO and EU leaders32
17:48 Thanks to Trump, Germany says it can’t rely on the United States. What does that mean?9
20:11 Zlatan Ibrahimovic has numerous offers, will stay in Europe14
19:46 Protesters, politics ‘without taboos’ greet Trump in Belgium31