MANILA - Environment Secretary Gina Lopez vented frustration on Wednesday that mines she ordered closed months ago remain open, aiming a broadside at a fellow cabinet secretary whose office she blamed for slowing appeals that can only be resolved by President Duterte.

The blast underlined tensions within Duterte's cabinet since Lopez ordered the permanent closure of 22 of the country's 41 mines early in February as part of a crackdown in the world's top nickel ore exporter designed to protect water resources.

Global nickel prices jumped on supply risks after the move, broadly supported by Duterte.

Lopez told reporters on the sidelines of a mining forum on Wednesday that appeals by mine operators directly to Duterte have become "stuck" in the office of the president's Executive Secretary Salvador Medialdea.

"It's only the president that can make a decision, but right now he can't even decide because the papers don't go to his office," Lopez said.

The combative environment minister - whose appointment has still to be ratified by Congress nearly 10 months after Duterte named her to the post - also rounded on Medialdea for suspending her order last month that mines where operations were suspended last year can only ship out nickel ore stockpiles if they pay a fee of 2 million pesos ($40,248) per hectare of disturbed land.

"He (Medialdea) stopped me. So now they're (miners) removing the stockpiles and I cannot stop them," she said. Lopez she wanted to meet with Medialdea but that he hasn't agreed to meet.

"It's my prerogative as (environment) secretary to issue that directive," Lopez said. "I'm totally within my rights."

Medialdea meanwhile insisted that appeals to the Office of the President go to the Executive Secretary and not directly to the President. He also denied that his move to suspend Lopez's order runs counter to Duterte's policy against destructive mining operations.

Medialdea said the Office of the President has not yet taken any legal position on the validity of the DENR requirement for mining firms to remit P2 million per hectare to a trust fund.

"The stay order issued by the OP (Office of the President) is not a final order but a mere provisional measure to prevent substantial damage that may result unless extracted ores are shipped out," he said.

Reuters reported last month that eight nickel miners suspended last year for environmental infractions were allowed to remove previously mined ore that could pose environmental hazards.

But Lopez required them to put 2 million pesos per hectare of disturbed land into a trust fund "to further mitigate the adverse impacts of the mining operations to the environment and to the affected communities".

Miners have questioned the hefty fee and secured permits from Medialdea to stay the implementation of Lopez's order.

Duterte reappointed Lopez this week after lawmakers deferred a decision to confirm or reject her appointment before Congress went into recess from March 18. They will resume hearings in May.

-- with a report from Dharel Placido, ABS-CBN News