China has found 225 new oil and gas fields within its borders over the past five years, Beijing officials said, a potential boost as the world is battered by energy shortages and cost increases.

Among the newly discovered sites are 13 oil fields holding more than 100 million tons and 26 gas fields with reserves exceeding 100 billion cubic meters, The Caspian Post reports via foreign media.

Though it didn’t specify how much of that fossil-fuel bounty is currently available, it said the country’s natural gas production could increase year by year and oil production was holding steady at 200 million tons per year, “thanks to the significant increase in the newly discovered energy reserves.”

Officials vowed to “resolutely safeguard our energy security,” and push ahead with oil and gas exploration.

The ministry said it has invested over 450 billion yuan ($66 billion) to almost double China’s known crude oil and natural gas reserves, compared with a decade ago.

The move comes as the effective closure of the Strait of Hormuz, a critical chokepoint in the transit much of the world’s oil, has led to a global energy shortage.

China is the world’s biggest energy importer. It imports around 10% of its oil from Iran and so isn’t insulated from the shocks. But it is so far faring better than most major economies due to a long-running energy self-reliance drive.

Chinese leader Xi Jinping this week called on cadres to “systemically address the challenges posed by external shocks, enhance the security of energy and resource supplies, and counter various uncertainties with the certainty of high-quality development.”