Trump had campaigned on a promise to "cancel" the Paris deal and sweep away Obama-era environmental regulations to help coal miners, whose output last year sank to the lowest level since 1978. The industry has been battered for years by surging supplies of cheaper natural gas, brought on by better drilling technologies, and increased use of natural gas to fuel power plants.
His administration has since sought to kill scores of pending regulations he said threatened industries like coal mining, and reversed a ban on new coal leasing on federal lands.
TAKING CREDIT
Both the coal industry and the Trump administration said the rising exports of both steam coal, used to generate electricity, and metallurgical coal, used in heavy industry, were evidence that Trump's agenda was having a positive impact.
"Simply to know that coal no longer has to fight the government - that has to have some effect on investment decisions and in the outlook by companies, producers and utilities that use coal," said Luke Popovich, a spokesman for the National Mining Association.
Shaylyn Hynes, a spokeswoman at the U.S. Energy Department, said: "These numbers clearly show that the Trump Administration's policies are helping to revive an industry that was the target of costly and job killing overregulation from Washington for far too long."
Efforts to obtain comment from exporters Arch Coal and privately held Murray Energy Corp were unsuccessful. Contura Energy, which emerged as part of Alpha Natural Resource's bankruptcy and restructuring, and filed for public offering in May, declined to comment.
A spokesman for Peabody Energy, the largest coal producer, though without a major export profile, said the United States was generally a "swing supplier of seaborne coal."
U.S. Energy Information Administration analyst Elias Johnson said the U.S. coal industry may now be better positioned to meet foreign demand because U.S. miners have learned to produce at lower cost, after coming through a series of recent bankruptcies.
"There's the possibility that the U.S. will become more of a primary player in the global coal trade market," he said.
But he added there are also plenty of reasons the spike in demand could be temporary. For one thing, U.S. coal production and transportation costs are much higher than for other producers such as Indonesia and Australia.
Because coal can often be transhipped from European ports before it is consumed, it is also hard to determine where shipments ultimately end up.
Johnson pointed out that some of the fuel shipped into Western Europe, for example, could be making its way to other places like Ukraine, which is having trouble securing coal from its separatist-held regions.
Trump said last month that his administration is offering more coal to Ukraine, but it was unclear how, given deals are typically worked out between companies.