Of Tamara Cohenpolitical correspondent in Hungary

Britain and European leaders will collectively react to Donald Trump’s win as they meet today to discuss security – and it casts a very long shadow.

As the enormity of the US result sinks in, Sir Keir Starmer will join a summit in Budapest hosted by the continent’s biggest president-elect cheerleader, Hungarian Prime Minister Viktor Orban.

Mr Orban, viewed with suspicion by the rest of the EU because of his ties to Vladimir Putin, is delighted by Mr Trump’s victory.

He told reporters at the European Parliament last month, where Hungary holds the rotating presidency, that he would open “more bottles of champagne if Mr Trump comes back”.

The European Political Community – which holds these summits every six months – was set up in the wake of Russia’s invasion of Ukraine as a chance for the EU27 to meet wider partners such as Britain, Turkey and the Caucasus countries, to discuss key security challenges, including conflict and irregular migration.

But the US outcome will completely overshadow the talks, as Mr Trump’s approach to Ukraine – and whether he tries to force a peace plan in which the Ukrainians must give up territory – will dominate the agenda. President Zelensky is present.

Mr Orban is also a supporter of a negotiated solution to the Russia-Ukraine conflict, while most of the rest of the EU largely supports Ukraine’s integrity – paving the way for potential tensions.

Sir Keir will chair the migration session and announce three new intelligence-sharing agreements with Balkan nations to tackle people smuggling.

But defense considerations are likely to come to the fore, with the prospect of US disengagement from Europe and pressure on NATO members not yet meeting the 2% defense spending target to step up.

Sir Keir has already faced questions at home about when he will deliver on his promise to spend 2.5%.

In a sign of the already changed atmosphere, the German defense minister, who met with his French counterpart yesterday, said after Trump’s victory: “They will be able to do less in Europe. We have to fill this gap to be more credible in terms of discouragement”.

The repercussions of events across the Atlantic will be very evident – we may get the first signals of how Europe will respond.