Explained | UK-EU Summit: What to know as officials gather to talk defense, trade and more

Top officials from the European Union and Britain are gathering in London on Monday, as the two allies pivot toward a post-Brexit future.

The gathering has been billed as a major reset of relations, and it is being especially closely watched given the context: Europeans and the British are trying to figure out how to reorient themselves in a world where the United States is a less-reliable ally on defense and trade.

Officials are expected to unveil a defense and security partnership, which could set out the broad contours of their future military cooperation. They are also expected to discuss matters related to trade, while committing to collaboration on other geopolitical issues.

Here’s what to watch as the two sides meet.

Who is meeting?

Keir Starmer, the prime minister of the United Kingdom, will host Ursula von der Leyen, the European Commission president, and Antonio Costa, the European Council president, as well as Kaja Kallas, the EU’s top diplomat, and Maros Sefcovic, the bloc’s top trade official. The event is expected to take place at Lancaster House in London.

What will they announce?

Officials are expected to announce a new defense agreement, which would be the biggest outcome of the summit. Policymakers on both sides have been negotiating for weeks on the plans, which are expected to set a future tone for relations at a critical moment, as Russia’s war in Ukraine grinds on and as the United States urges European nations to ramp up their own military spending and shoulder a greater responsibility for their own security.

This could lay the groundwork for Britain to eventually become part of European defense efforts, including a 150 billion euro (about $168 billion) loan program meant to help with joint procurement and investment. That plan is limited to EU nations and select allies, and Britain has been eager to take part.

Trade and immigration will also be on the agenda. The goal is “a strengthened partnership with the European Union,” Starmer’s office said in talking points published over the weekend, saying that would be “good for our jobs, good for our bills and good for our borders.”

What have been the sticking points?

Reaching an agreement has not been seamless. Europeans — and particularly coastal countries such as France and Belgium — insisted that London extend access to British fishing waters for more than a few years. Fishing is a politically sensitive topic, and the British side was hesitant to make that move.

Likewise, tensions emerged over a youth mobility scheme, which is meant to give young people and students from both sides access to each other’s countries. Europe was pushing for lower tuition for EU students who study at British universities, asking for the same fees that local students pay. Their counterparts argued that granting that access would be too expensive.

The ultimate deal is expected to be broad-brush — a plan to collaborate in the future, but one with details that remain to be determined.

“There’s a lot of negotiation to be done on the other side” of the summit, said Mujtaba Rahman, managing director for Europe at the research firm Eurasia Group.

What are the politics?

The EU has been working hard to clinch trade deals and shore up alliances as it tries to prove to the United States that it is an economic and diplomatic power to be reckoned with.

President Donald Trump has hit Europe with several waves of tariffs — both across-the-board and industry-specific — and is only beginning to make deals to de-escalate the situation. While Britain has struck a preliminary deal to avert much-higher tariffs, the EU has made limited progress toward one.

And both partners see a need for greater collaboration in a world where the United States is a less-willing supporter of its traditional allies. Britain’s firms and its defense industry could benefit from being included in Europe’s push to rearm, and Europe could benefit from access to British military capabilities.

But both sides face domestic pressure to defend their own interests.

In Europe, concerns about reaching a fair deal that included commitments on issues such as energy and fisheries lingered late into the negotiations. And in Britain, politics could give Starmer a reason to take a somewhat cautious approach as the nation draws closer to the bloc it left five years ago.

The insurgent Reform UK party, led by Nigel Farage, a Trump ally and famous Brexit backer, has been taking particular aim at the proposed youth mobility plan. Given the party’s success in recent local elections, that pressure could give Starmer a reason to avoid too cozy of a tone — or risk political fallout.