He said the challenge was now on management, staff and the local community to work together to ensure that benefits continued to flow to all the stakeholders, The National newspaper reported.
Bristow made these comments during a question-and-answer session with employees at the mine during his brief visit to the country recently.
"When you look at the current plans of Porgera, it has the potential to be able to deliver 500,000 ounces for the next 10 years," he said.
"The geologists are indicating that there's potential for another 10 years after that."
Bristow said the biggest challenge for the operation was costs associated with running the mine.
He said the reason he had visited Porgera was to understand the project.
"As you know today, Barrick is the biggest gold miner in the world and we want to be the most valued. We must ensure that our shareholders trust us, our host countries governments trust us, and that our workers are proud to work with us in our mines. That's what we want to be."
Bristow also took the opportunity to talk about the Porgera Joint Venture (PJV) partners and their commitment to the future of the mine.
"I'm here to explain to you that Barrick is back along with Zijin, because this is a joint venture," he said. I intend to work with you and the management team, and put Porgera back on the map. We want to renew our special mining lease. We are prepared to invest in the future of this mine and its people. It's not only an asset for Porgerans. It's a national asset that makes its contribution to everyone in this country," Bristow said.