Confiscated Vietnamese fishing boats are blown up by Indonesian authorities in February. Indonesia takes a hardline stance on incursions into its waters.

New Zealand's experience in tackling illegal fishing around the Pacific can be used to help Indonesia as the country faces incursions into its own national waters, Prime Minister John Key says.

However, Key says there are no set plans for how a deal between the two countries on illegal fishing will be put into practice.

After meeting in Jakarta's Presidential Palace, Key and Indonesian president Joko Widodo pledged to work together to combat "illegal, unreported and unregulated fishing" and promote sustainable fisheries.

SAM SACHDEVA/FAIRFAX NZ John Key says a deal with Indonesia to tackle illegal fishing is about sharing more information between the two countries.

Indonesia has taken an explosive approach to what it deems to be illegal fishing in its waters.

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In April, the country blew up 23 fishing boats from Vietnam and Malaysia that it said were poaching in Indonesian waters, while it has scuttled more than 170 boats in the last two years.

Indonesia has more than 460,000 fishing boats which reportedly account for three percent of GDP, making them a vital part of the country's economy.

Their fishermen have been caught up in the dispute over the South China Sea, with Chinese fishermen encroaching on Indonesian waters around the Natuna Islands.

Key said the agreement between the two countries was "just about being a good international citizen".

"It's protocol, it's the way we work together, it's information we might share, it's experiences we've had - there's no sort of set thing that we'll go and do."

SHARING INFORMATION ON ILLEGAL FISHING

The deal set out a "framework" for cooperation, but the details would depend on whether a New Zealand boat was in the area, or officials had gathered information about a potential fishing breach.

Key said the experience of and lessons learned from helping Pacific nations to fight back against illegal fishing could be shared with Indonesia.

"Really all we're doing here in Indonesia is a similar kind of approach, saying this is how we do things, these are the experiences we've had, this is how we might share some ideas together."

New Zealand's own experience with protecting its large fishing areas could also provide useful information, he said.

"We have very large exclusive economic zones from New Zealand's point of view, large fishing rights, and we know that we protect our own fishing rights appropriately because it means a lot to the New Zealand economy, and it means quite a lot to the Indonesian economy."

Key will fly out of Indonesia on Wednesday morning (NZ time), after spending three days in the country to talk trade and greater cooperation.

With a population of over 250 million, Indonesia is projected to become the world's seventh-largest economy by 2030.

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