Under the current coal leasing program, "there is no probability that actually you can do with that lease what's intended with it," he said, comparing federal lease sales to junk bonds.
"Rather than selling a junk bond, we need to look at maybe selling a double-A bond," the former Montana congressman told reporters after an introductory speech to Interior employees. "I think we all benefit from that."
The Interior Department "needs to do a lot of homework upfront, look at that (lease) and value it correctly," Zinke said. "And also give the buyer a probability that there is a return on investment."
As a former Boy Scout, Zinke said he wants to "make sure when I leave the campground it's returned to the same or better" condition. "I think America on our public lands has the same view," he said.
The Obama administration imposed a three-year moratorium on new coal leases on federal lands in January 2016, arguing that the $1 billion-a-year program must be modernized to ensure a fair financial return to taxpayers and address climate change.
The coal program has remained largely unchanged for more than 30 years despite complaints that low royalty rates and a near-total lack of competition have cost the government hundreds of millions of dollars a year in untapped revenue.
The moratorium imposed by then-Interior Secretary Sally Jewell drew praise from environmental groups and Democrats, but condemnation from Republicans who called it another volley in what they asserted was a "war on coal" waged by President Barack Obama.
At least 30 mining applications in nine states have been blocked under the directive, according to a federal list obtained by The Associated Press. Some of the largest projects are in the Powder River Basin of Wyoming and Montana, the nation's top coal-producing region.
More than 40 percent of U.S. coal production, or about 450 million tons a year, comes from public lands in Wyoming, Montana and other Western states, bringing in more than $1 billion in annual revenue.
Coal reserves under lease before the moratorium was imposed can continue to be mined.
In a speech to Congress this week, Trump boasted about "a historic effort to massively reduce job crushing regulations," including some that threaten "the future and livelihoods of our great coal miners."
Trump signed a law last month overturning an Obama administration rule to prevent coal mining debris from being dumped into nearby streams.