'All along, I've been proven to be right'

US President-elect Donald Trump said on Wednesday that attacks this week in Berlin and Ankara proved he was correct to propose curbing Muslim immigration to the United States.

"What's going on is terrible, terrible," Trump told reporters, when asked about the truck attack that killed 12 people at a Christmas market in Berlin and the killing of Russia's ambassador to Turkey.

Islamic State claimed responsibility for the Berlin killings though US officials say they had seen no evidence that the militant group had directed the attack.

The assassin in Turkey shouted about the war in Syria as he shot dead the envoy from Moscow, which aids Syrian President Bashar al-Assad against rebels in that country's civil war.

Trump was asked by reporters outside his Mar-a-Lago resort in Palm Beach, Florida, if Monday's violence would affect his consideration of a ban on Muslims entering the United States or of a registry for immigrants from Muslim countries.

"You know my plans. All along, I've been proven to be right. 100 percent correct. What's happening is disgraceful," Trump said.

On Monday, Trump issued a statement about the Berlin attack in which he said that Islamic State and other Islamist militants "continually slaughter Christians in their communities and places of worship as part of their global jihad."