Berlin attack affirms my proposal to ban Muslims: Trump

US President-elect Donald Trump has said that the deadly truck attack on a Christmas market in Berlin proved that he was correct to propose barring Muslims from entering the US.

"All along, I've been proven to be right. One-hundred-percent correct. What's happening is disgraceful," Trump told reporters on Wednesday outside his Mar-a-Lago resort in Palm Beach, Florida.

According to a report in the Washington Post, Trump did not walk back the proposals after he was asked by the media whether he was rethinking or re-evaluating them in the wake of a fresh terrorist attack in Berlin.

"You know my plans," Trump said.

He went on to add that the attack on a Berlin Christmas market, which was claimed by the Islamic State, had vindicated him. German authorities were seeking a 24-year-old Tunisian migrant, who they say has ties to Islamist extremists, in connection with the attack, which killed 12 people.

Earlier, Trump had in a statement called for a temporary ban on Muslims entering the US and has expressed openness to a registry of Muslims already in the country.

However, the proposal was sharply criticised by Republicans and Democrats alike.

He was also asked about his characterisation of the Berlin attack as an attack on Christians.

"The IS and other terrorists continually slaughter Christians in their communities and places of worship as part of their global jihad," Trump had said in a statement issued after the attack on Monday.

On Wednesday, Trump appeared unfamiliar with the statement issued in his name.

"Who said that?" Trump countered, challenging the reporter. "It's an attack on humanity and it's got to be stopped."