Indonesia is prepared to pay a ransom of 5bn rupiah (US$332,000) to a Papuan separatist group to secure the release of New Zealand pilot Philip Mehrtens, but talks have stalled five months after his kidnapping.

With Indonesia President Joko Widodo arriving in Australia on Monday night, Papua Police spokesman Ignatius Benny Ady Prabowo said the ransom was one of several ­demands proposed by the West Papuan National Liberation Army (TPNPB) a few weeks after the first video of the Susi Air pilot was released. The group also wanted weapons, food and medical supplies.

“Since then, the group has never engaged in negotiations with us. Of course, we cannot provide weapons … but the requested amount of Rp 5bn (US$332,000), it can still be negotiated,” he said.

In a video released in late May and verified by Papua Police, Captain Mehrtens was recorded saying that if Indonesia did not fulfil demands, he would be executed within two months.

Indonesian authorities insist they do not want open conflict with the group and continue to rely on local religious leaders to negotiate the release of the pilot, after the botched rescue operation in mid-April that killed at least six Indonesian soldiers (the Indonesian military insists there was only one casualty).

As he prepared to fly to Australia for a state visit, Jokowi, as the Prime Minister is known, said Indonesia would prioritise negotiation, but he did not elaborate.

“Actually we have done many things there, but I cannot reveal it here,” he said.

Jokowi said he would go to Jayapura, the capital of Papua province, on Thursday and Friday, his second visit to the easternmost region since the kidnapping in February.

The prolonged hostage situation has worsened the access to basic logistical needs for locals living in the most remote locations as pilots have refused to fly planes to unsafe areas.

Akouboo Amatus Douw, the Brisbane-based representative of the TPNPB, insisted the group had “proven in the first three months guaranteeing the life of the Kiwi pilot” and is not planning to kill innocent people.

“This New Zealand pilot is not the enemy of TPNPB, even the Indonesian troops are not actually their enemy, their real enemy is colonialism and illegality in our holy land,” said Douw, one of 43 Papuans granted Australian asylum in 2006, over the weekend.

He called on Jokowi to withdraw the Indonesian military and open an “internationally mediated peace negotiation on the future destiny of West Papua and the release of this foreign citizen, Philip Mehrtens”.

Papua has been subject to a simmering insurgency since the resource-rich region was controversially brought under Jakarta’s control in 1969.