For once it will not all be about Brexit. Theresa May hasn't got much to say about British plans today that the other 27 haven't already heard, and anyway they are sticking rigidly to their 'no negotiation before Article 50 notification' rule.

Instead the talk will be about an even bigger cloud on the horizon than Brexit. Donald Trump. Do not underestimate the concern there is in the Chancelleries of Europe about where the world may be heading under Mr Trump, and the impact he may have on Europe.

The President of the Council, Donald Tusk, wrote an extraordinary letter to his fellow leaders this week warning them of the threats the continent now faced. An assertive China. Russian aggression. Radical Islam. So far, nothing too surprising. But then the bombshell, as he listed "worrying declarations by the American administration".

Suddenly here is Europe's oldest ally, closest partner for most of the 20th Century, fellow defender of 'Western values' being listed as one of the external threats to the future of the EU. We are truly living in changed times.

All of which makes Mrs May's appearance at this 'informal summit' (she wasn't originally intended to come) rather interesting, because she is the only one among them who has actually spent time with the new President.

The other 27 were delighted that on her Washington visit she was able to moderate significantly his language and position on the future of NATO, but they remain highly suspicious of her intentions towards Trump. The 'holding hands' picture did not go down at all well. They have heard Trump speak of welcoming a break-up of the EU, and they are concerned the UK may be sympathetic to that aim if there isn't a generous Brexit deal on the table.

She will go out of her way to try and reassure them on this point, insisting that it remains overwhelmingly in our interests, and that of the rest of the world, that the EU should succeed. But she will also remind them of the importance of European members of NATO doing their bit on defence, particularly of hitting the 2% of GDP defence spending target

Much of the talk today will be of how to control the migration crisis in the Mediterranean, an issue of particular importance to the hosts, Malta, which lies on the refugee route between Libya and Italy. Once again Theresa May take the chance to point out how much the UK is already contributing to this EU effort.

This may be the last EU summit for a while not to be dominated by the single issue of Brexit. By the time of their next scheduled meeting in Brussels next month, the Article 50 notification letter may already have been delivered and the talk will be of little else.

Or maybe it won't. Donald Trump will have spent another 5 weeks in the Oval office, and who knows how the world will look by then.