South Korean President Yoon Suk-yeol gave the green light on Monday to conduct exploratory drilling for potentially vast oil and gas prospects found off the east coast of the nation that is one of the world's largest energy importers.

The possibility of the area containing as much as 14 billion barrels of oil and gas is "very high," Yoon told a news conference, citing a study that he said has been reviewed by experts and industry groups.

"Today, I approved the Ministry of Trade, Industry and Energy to go ahead with the drilling for exploration deep in the east sea," Yoon said.