UK Prime Minister Keir Starmer landed in Berlin late Tuesday ahead of talks with German Chancellor Olaf Scholz, in his first bilateral trip since taking office last month.
The British leader has pledged to rebuild trust with European allies, damaged by Brexit, and Starmer and Scholz are set to discuss launching a new partnership. He will then travel to Paris.
Starmer's Labour party had said it would seek a security and defence treaty with Germany if it won the July 4 general election, which it did by a landslide -- propelling him to the premiership.
The new bilateral deal will take several months to negotiate and be finalised early next year, according to Starmer's Downing Street office.
A "key pillar of the UK's wider reset with Europe", it will build on a bilateral defence agreement currently being negotiated and expected to be finalised later this year.
The new treaty is aimed at boosting business and trade, deepening defence and security cooperation, and increasing "joint action on illegal migration," Downing Street said.
"We have a once in a generation opportunity to reset our relationship with Europe and strive for genuine, ambitious partnerships that deliver for the British people," Starmer will tell Scholz, according to his office.
"We must turn a corner on Brexit and fix the broken relationships left behind by the previous government," he will add.
The UK leader will note that strengthening ties with Germany and France is "crucial".
"Not only in tackling the global problem of illegal migration, but also in boosting economic growth across the continent and crucially in the UK," he is set to say.
Starmer will be welcomed to the German capital with military honours on Wednesday morning.
He will then hold talks with Scholz that are also likely to focus on military support for Ukraine, with both countries under pressure over their aid for Kyiv.
Starmer, 61, a former human rights lawyer and chief state prosecutor, supported Britain remaining in the EU during the 2016 Brexit referendum and was once Labour's Brexit spokesman.
He has ruled out rejoining the European single market, customs union or freedom of movement -- to avoid reopening what remains a thorny issue among British politicians and the public alike.
But he does want to negotiate a new security pact with the bloc and a veterinary agreement to ease border checks on agricultural foods, as well as an improved trading deal.