BRUSSELS (AFP) - Belgium's new interior minister sparked an uproar on Monday after saying that Flemish collaborators with the Nazi occupiers in World War II "had their reasons", touching a raw nerve in a sharply divided country.

Jan Jambon is the right-hand man of Bart De Wever, whose nationalist New Flemish Alliance (N-VA), based in Belgium's north, dominates the centre-right coalition led by Prime Minister Charles Michel from the French-speaking south.

"The people who collaborated with the Germans had their reasons," Jambon told La Libre Belgique daily, noting that he was not alive at the time to judge.

The new coalition was sworn in on Saturday and faces a vote of confidence in parliament on Thursday which it is expected to win.

Jambon made his comments in an interview during which he was asked about a speech he made to a 2001 meeting organised by the Sint-Maartensfonds, an association for Flemish fighters who fought for Germany against Russia on the eastern front.

"I defy anyone to find a phrase, a text where I defend collaboration. Collaboration was a mistake," Jambon told La Libre Belgique.

He said he had already explained his presence at the meeting where he spoke for the VVB Flemish populist movement, of which he remains a member.

In a statement later Monday, Jambon forcefully rejected any suggestion he condoned collaboration and said his comments had been taken out of context and maliciously exploited.

"Collaboration was a mistake. I have always been clear on this point. It was a historic mistake with heavy consequences," he said. "If my words were misunderstood and caused offence, I regret it."

Belgium's wartime history is a divisive chapter in an already sharply divided country, where the split between the Flemish and French-speaking communities led to a five-month delay in forming the new government.

Benoit Lutgen, head of the Francophone opposition Humanist Democratic Centre (CDH) party, condemned the appointment of Jambon, calling him "a divisive personality who thinks turning up to right-wing meetings counts for nothing".

"We are not going to ask for his resignation just three days after taking office but this is really shocking," Lutgen said.

The new Belgian government comprises three Flemish parties led by the N-VA, and Michel's Reform Movement (MR).

The N-VA emerged as the largest single party with 33 per cent of the vote in May 25 elections and took most of the top cabinet posts but De Wever declined to take a portfolio and stayed on as mayor of Antwerp.

With only four women in the 18-member cabinet, and no visible ethnic minorities, the Belgian press said the new government did not really reflect the country's diversity.

The outcry over Jambon's remarks is not the first time Belgian politicians have landed in hot water over comments about the war.

De Wever himself angered Francophones in 2010 when he accused them of historical amnesia over wartime collaboration within their own ranks.

Many people in Flanders believe that the purge that followed the liberation of Belgium mainly targeted Flemish collaborators while prosecutions were rarer in French-speaking Wallonia.