Chinese investors will all have to go through a national security review, Natural Resources Minister Jonathan Wilkinson said Tuesday.

The approval process for the quotas has been delayed this year, raising concerns from nickel smelters who are facing depleting ore stock.

Unleashing the stockpile of semi-processed metal could generate between $200 million and $300 million based on today’s copper prices.

Panama holds presidential elections in May, and the future of Cobre Panama mine has emerged as a flash point among opponents and supporters of the mine.

Ecuador will invest $100 million in the Condor project and $157 million in the La Plata project.

The miner also expects to secure authorization to sell more than 120,000 metric tons of copper concentrate stored near a port.

The falling charges have threatened to cut output in the world's top producer of refined copper.