UK premier Rishi Sunak will talk defence and security with German Chancellor Olaf Scholz on Wednesday when the British leader makes his first trip to Berlin since becoming prime minister 18 months ago.

Discussions are expected to focus on Ukraine, defence spending levels, and a push by Germany to bolster NATO's air defences in Europe amid Russia's relentless missile strikes on Ukraine.

"At this dangerous moment for the world, the UK and Germany are standing side by side to preserve security and prosperity at home and across our continent," said Sunak, haling "a new chapter" in the countries' relationship.

Sunak's visit to Berlin is the second day of a two-day trip to Europe. He visited the Polish capital Warsaw on Tuesday where he pledged to gradually increase UK defence spending to 2.5 percent of GDP by 2030.

Sunak said that the West was facing its most dangerous period since the end of the Cold War, with Russia's assault on Ukraine in its third year, but also the threat of escalation in the Middle East.

NATO countries are facing pressure to raise defence expenditure in the face of these global threats.

More of NATO's European members -- including heavyweights France and Germany -- have increased their defence spending recently to meet the alliance's two percent of GDP target.

But EU chief Ursula von der Leyen recently warned that more needs to be done and Brussels is set to come up with further proposals for financing the defence push by a summit of EU leaders in June.

It has put forward a 1.5-billion-euro ($1.6-billion) strategy to step up defence production, but officials say this is nowhere near sufficient.

"Germany and the UK are the two largest defence spenders in Europe and are the two countries which have been at the forefront of providing support to Ukraine," Sunak said in Poland on Tuesday.

"I'm confident that that will continue and we are actually in the process of strengthening our defence and security co-operation with the Germans," he added.

Sunak and Scholz are due to announce plans for a joint endeavour to develop remote-controlled Howitzer artillery systems that will be fitted to Boxer armoured vehicles.

They are also likely to discuss Germany's common air defence project, the European Sky Shield Initiative.

Berlin has urged allies to buy deterrence systems together and the UK, which left the European Union in early 2020, is among some 20 countries to have signed up to the plan.

The project would involve joint procurement for short-, medium- and long-range systems, including the German-made Iris-T, the American Patriot system and the US-Israeli Arrow 3.

France has so far declined to sign up to the pact, with officials there arguing instead for an air defence system using European equipment.

Sunak and Scholz are due to hold a press conference at 1:45 pm (1145 GMT).