European Union leaders have signalled caution and confusion about America's potential new direction under Donald Trump.
European Commission president Jean-Claude Juncker said he did not feel threatened by the new president, but "there is room for explanations because of the impression that the new administration does not know the EU in detail but in Europe details matter".
Austria's Christian Kern said: "Today we have pretty mixed feelings, to be honest, because the tangible aspects of Mr Trump's policies are raising some concerns.
"It's not a threat, it could be a catalyst for a strong, more united Europe. It is an alarm call to see if we are the right track."
French President Francois Hollande stressed the need for a united Europe in the face of uncertainty from the US.
Asked what he thought of leaders, like those in Hungary and Poland, who were leaning towards Mr Trump, Mr Hollande said: "Those who want to forge bilateral ties with the US are of course well understood by the public.
"But they must understand that there is no future with Trump if it is not a common position. What matters is solidarity at the EU level. We must not imagine some sort of external protection."
German chancellor Angela Merkel said: "Europe has its destiny in its own hands. I believe that the more strongly we make clear that we will define our own role in the world, the better we will be able to cultivate our transatlantic relationship."
More than 700 people have been rescued from the Mediterranean in the last 36 hours.
The UK will offer help to Latin American and Asian countries which need migrants, to be able to take them in.
The European Union summit will see leaders discuss the migrant crisis between Italy and Libya, defence and Nato, and Donald Trump.