A barge loaded with Illinois Basin coal sits in the Ohio River on April 3, 2017 at Cairo, Illinois. Scott Olson | Getty Images

China, the world's biggest coking coal importer, is scrambling to cover Australian supply disruptions after Cyclone Debbie knocked out mines and rails by turning to an unusual source: the United States. Debbie, which hit Australia's Queensland state last week, caused the evacuation of several mines and damaged coal trains supplying export terminals, triggering two miners - Yancoal Australia and QCoal - to declare force majeure on its deliveries. With other miners like BHP Billiton and Glencore also affected by the storm's fallout, more disruptions may follow. Force majeure is a commercial term that means a buyer or seller cannot fulfill their obligations because of outside forces. It is typically invoked after natural disasters or accidents. Australia is the world's biggest coking coal exporter and is China's largest supplier. With markets there closed on Monday and Tuesday, its steel makers are clambering to find alternative supplies. "Markets may be closed Monday and Tuesday but there's certainly activity. The Chinese are fixing cargoes from the United States in order to replace the shortfall from Australia," one coal trader with knowledge of the matter said, speaking on the condition of anonymity as he was not cleared to talk about commercial deals. "More will make its way from the U.S. to China very soon," he said.

It was not immediately clear which American miners were providing the supplies but Thomson Reuters Eikon data shows that China already has imported more than 500,000 tonnes of U.S. coking coal in 2017, ending a two-year stretch when no coking coal was shipped between the two countries. More than 427,000 tonnes of U.S. met coal imports were counted in February by the Chinese government that likely arrived in January, said Chuck Bradford of Bradford Research, who has access to the data. The coal sold for nearly $190 per tonne, he said. Arch Coal did not immediately respond to a query on whether it had exported the coal to China this year. George Dethlefsen, Corsa Coal Corp's chief executive, said his company has been overwhelmed with inquiries for cargoes over the past few days from customers in Asia. "Right now we, like everyone else, are trying to figure out what tons are available and what we can produce to fulfill potential new orders," he said. Alpha Natural Resources, which emerged from bankruptcy last year, declined to comment. President Donald Trump has promised to revive the U.S. coal industry and issued an executive order last week to dismantle former President Barack Obama's regulations on the sector. Luke Popovich, a spokesman for the National Mining Association trade group, said it was not clear that the demand had any link to the administration's push to axe regulations.