GDANSK (AFP).- Prince William and his wife Kate said Tuesday they were "intensely moved" by their visit to a former Nazi German concentration camp, on a diplomacy tour of Poland and Germany following the Brexit vote.

"All of us have an overwhelming responsibility to make sure that we learn the lessons and that the horror of what happened is never forgotten and never repeated," the royal couple said in the visitor's book of the site near the Baltic port city of Gdansk.

"We were intensely moved by our visit to Stutthof, which has been the scene of so much terrible pain, suffering and death," added the message signed "William Catherine".

Kate and William also met five former camp prisoners, including two Britons, while at the site that Nazi Germany set up in 1939.

While not officially tied to British-EU diplomatic relations, the royal couple's five-day tour of Poland and Germany appears to be a charm offensive by Britain, whose status in Europe has taken a hit since its shock decision to exit the European Union.

Poland in particular is concerned by Brexit as there are nearly a million Poles in Britain whose future remains unclear.

Kate and William also on Tuesday visited the new Gdansk Shakespeare Theatre, as well as the city's European Solidarity Centre museum, which tells the story of the Soviet bloc's only free trade union.

There they met with freedom icon Lech Walesa, who won the Nobel Peace Prize as the leader of the Solidarity trade union and later became Poland's first democratically elected president after negotiating a bloodless end to communism for the country in 1989.

William, who is second in line to the throne, and Kate, the Duchess of Cambridge, will fly to Germany on Wednesday to continue their tour.


© Agence France-Presse