Turkish President Recep Tayyip Erdogan on Tuesday called on New Zealand to restore the death penalty for the gunman who killed 50 people at two Christchurch mosques, warning that Turkey would make the attacker pay for his act if New Zealand did not.

Australian Brenton Tarrant, 28, a suspected white supremacist, was charged with murder on Saturday after a lone gunman opened fire at the two mosques during Friday prayers.

"You heinously killed 50 of our siblings. You will pay for this. If New Zealand doesn't make you, we know how to make you pay one way or another," Erdogan told an election rally of thousands in northern Turkey. He did not elaborate.