"We're going to check for unsafe conditions, and we're going to correct any unsafe conditions before we mine another lump of coal," Manchin said.
A miner was killed at an underground mine when a wall support popped loose, said Caryn Gresham, a spokeswoman for the state Office of Miners' Health Safety and Training.
The second fatality occurred at a surface mine when a bulldozer struck a gas line, sparking a fire and killing the operator, said Dirk Filpott, a spokesman for the federal Mine Safety and Health Administration.
The deaths brought to 16 the number of mining-related fatalities in West Virginia this month.
"West Virginia remains committed to putting the safety of every one of our miners first and foremost, far above any production that might come from that mining operation," Manchin said at a news conference.
Last week, into law Thursday, saying the requirements for better communications, underground oxygen supplies and faster emergency responses would help prevent tragedies like the two that killed 14 miners this month.
"We want to be the benchmark everyone looks to when they mine," Manchin said during the signing ceremony, attended by some of the miners' relatives. "The sacrifice you all have made will change mining in this country."
State lawmakers passed the legislation unanimously just days after a Jan. 19 mine fire killed two men, and about three weeks after an explosion at the Sago Mine across the state resulted in the deaths of 12 miners.
The governor said he did not know how long it would take the state's 229 surface and 315 underground mines to conduct safety checks, which would include reviewing mine conditions, safety checklists and designated escape routes.
As he issued his call for a production shutdown, the governor was joined by Bill Raney, president of the West Virginia Coal Association.
"If you don't have a safe mine, you don't have a productive mine," Raney said.
West Virginia is the nation's second-largest coal producer, after Wyoming. It was not immediately clear how much a shutdown might cost the state's industry, Raney said.