It was unclear when the pilot, Philip Mehrtens, who was kidnapped exactly a year ago when he landed a small commercial plane in a mountainous area, would be released.
Terianus Satto of the West Papua National Liberation Army (TPNPB), one of several groups fighting for Papua's independence from Indonesia, said in a statement that Mehrtens will be released to "protect humanity and...human rights".
"TPNPB will return the pilot Philip Max Martherns to his family through the jurisdiction of the Secretary General of the United Nations," he said.
New Zealand's ministry of foreign affairs and trade did not immediately respond to a request for comment.
A low-level but increasingly deadly battle for independence has been waged in the resource-rich western half of the island of Papua since it was controversially brought under Indonesian control in a vote overseen by the United Nations in 1969.
Indonesia's government and military, which have struggled to stamp out the separatist movement, had said they were in negotiations to free the pilot.
