BOISE, Idaho (AP) — Federal officials have given a giant airtanker approval to fight wildfires in the U.S., but a lack of contracts currently limits the aircraft to California and one county in Colorado.

The U.S. Department of Agriculture's Interagency Airtanker Board issued the 17-month interim approval on Tuesday for the aircraft capable of carrying 19,200 gallons (72,700 liters) of liquid.

Global SuperTanker Services CEO Jim Wheeler said Wednesday the company is close to signing a contract with two states.

"The next step is for us to try to get a contract with the Forest Service," he said.

Such a contract would allow a state to be reimbursed by the federal government if the aircraft fought fires in that state. Wheeler said he hopes to get such a contract this year so the aircraft can fight fires across the West.

"The worst of the fire season is not over," he said. "It's just beginning."

During the interim approval, Global SuperTanker "must take steps to ensure its 747 aircraft delivers fire retardant in a manner that is effective and efficient and aids firefighting efforts on the ground." the Forest Service said in a statement Wednesday to The Associated Press.

The company has been fighting the Forest Service over a contract limiting firefighting aircraft to 5,000 gallons (18,900 liters).

"I scratch my head over that one," Wheeler said, noting the Forest Service has declined to give a reason for the limit. But he said he hoped to get past that problem this year or next. The company filed a protest over the limit, but it was rejected by the Forest Service.

The Forest Service said in its statement Wednesday that it's working to announce contracts for large air tankers.

The National Interagency Fire Center says about 40 active large wildfires are currently burning in the U.S.

To date, the current wildfire season has claimed about 8,000 square miles (20,720 sq. kilometers), about 2,400 square miles (6,200 sq. kilometers) above the 10-year average.

The 747 is currently in Victorville, California, having just completed routine maintenance.

"We're ready to go," Wheeler said.