Britain's King Charles III will begin his first state visit when he travels to Germany on Wednesday, having postponed a trip to France due to widespread political protests.

Charles will arrive in Berlin and undertake engagements there and in Brandenburg before heading to Hamburg during the three-day tour.

The decision to visit close neighbours first is widely seen as an attempt to build post-Brexit bridges, with German President Frank-Walter Steinmeier calling it "an important European gesture".

Steinmeier and German first lady Elke Buedenbender will welcome Charles and Queen Consort Camilla with military honours at Berlin's Brandenburg Gate, the first time the famous landmark has provided a backdrop for receiving a state guest.

The couples will then travel to Steinmeier's Bellevue Palace in the city centre, where he will host a state banquet for the royals.

The king will on Thursday make a speech in the German federal parliament and meet refugees recently arrived from Ukraine.

Steinmeier and the royal couple will then visit a German-British military unit in the surrounding state of Brandenburg.

The king will move on to the northern port city of Hamburg on Friday, where he is due to tour a renewable energy project.

Charles and Steinmeier will lay wreathes in the ruins of the city's St Nikolai church, which was destroyed during a World War II air raid, and which now stands as a memorial.

The UK monarch will also sign the city's "Golden Book", which he previously signed in 1987 during a visit with then-wife Princess Diana.

Charles will be keen to kick off his first state visit as king after his trip to France, which was meant to take place earlier this week, was postponed in the wake of violent pension reform protests.

The visit was intended to highlight warming Franco-British relations, but instead underlined the severity of demonstrations engulfing Britain's neighbour just 10 months into President Emmanuel Macron's second term. (AFP)