MANILA – Philippine President Rodrigo Duterte on Monday warned mining companies to strictly follow tighter environmental rules or shut down, saying the Southeast Asian nation could survive without a mining industry.

"We will survive as a nation without you," Duterte told a media briefing, referring to the country's miners. "Either you follow strictly government standards or you close down."

It was the boldest statement yet from Duterte against domestic miners that he warned in the weeks before he took office on June 30 to "shape up" and to "stop spoiling the land."

The Philippines has so far suspended the operations of seven domestic nickel mines for failure to comply with environmental regulations.

Environment and Natural Resources Secretary Regina Lopez, who began an audit of all mining sites on July 8, last week vowed to close more operations as public complaints mount against those causing environmental destruction.

"You try to castigate Gina Lopez for being strict, and yet you destroy the land, destroy the soil, and then you get rich," Duterte said, again referring to miners without giving names.

He said he can forgo the annual 40-billion Philippine pesos ($852-million) in government revenue from the mining industry.

Some mining executives say the sector is being unfairly targeted.

"The industry is using less than 20 000 ha out of the 30-million hectares comprising the total land area in the Philippines," Dante Bravo, president of Global Ferronickel Holdings, the Philippines' second-biggest nickel ore miner.

"And we are contributing so much to the national economy and local development. So, I think we should be treated fairly," Bravo told Reuters.

The Philippines is the biggest supplier of nickel ore to top consumer China, taking over from Indonesia after that country banned shipments of unprocessed mineral ores in 2014.

Mining contributes less than 1% to the Philippine economy, with a large chunk of minerals from gold to copper and nickel remaining untapped, according to the country's Mines and Geosciences Bureau.

Of nine-million hectares identified as having high mineral reserves, only 3% is being mined, according to the Bureau.

The suspension of nickel mines in the Philippines and the risk of more closures lifted global nickel prices to an 11-month high of $10 900/t on July 21. It peaked at $10 800 on Monday after rising nearly 13% in July, the biggest monthly gain since April 2014.