French energy group Total has declared "force majeure" on its $20 billion Liquified Natural Gas project in Mozambique, and withdrawn all its staff from the site.
Monday's (April 26) announcement follows attacks by Islamic State-linked insurgents last month on the town of Palma.
Total, which aimed to produce its first cargo from the Afungi project in 2024, suspended work on March 27 after the militant attack.
But declaring force majeure implies a weightier suspension, and allows the company to cancel contractors.
Dozens of civilians were killed in Palma in the northern Cabo Delgado province, near gas projects worth $60 billion.
The attacks have dealt a blow to the plans by Total and rival Exxon Mobil to turn the African nation into a major LNG producer to rival Australia, Qatar, Russia and the United States.
Total said it had made the decision because of the "evolution of the security situation".
On Monday the chairman of Mozambique's National Petroleum Institute said authorities were working to restore "normal security conditions".
He added that the project had not been abandoned.
Total said it was too early to provide an updated project schedule.
The company secured a $14.9 billion debt financing package in July, but said on Monday that its lenders had agreed to pause the debt drawdown.