Los Angeles, September 5 The battle against wildfires sweeping across the drought-stricken western United States, mobilising 30,000 firefighters, could be the costliest on record with $1.23 billion spent so far, officials say. Last week alone, a record $243 million was spent fighting more than 40 massive wildfires, said Jennifer Jones, spokeswoman for the US Forest Service, most of them in Washington state, which along with Alaska has borne the brunt of the disaster. “Overall, the US Forest Service has spent $1.23 billion,” Jones told AFP, adding that the bill could get steeper as fires continue to blaze in some western US states. The all-time record for firefighting costs in the United States — $1.65 billion — was set in fiscal 2002. As of Friday, the flames had scorched nearly nine million acres (3.5 million hectares) so far this year, more than half in Alaska, the National Interagency Fire Centre said. “Three new large fires were reported (on Friday) and three contained,” the agency said in a statement. “The majority of the fire activity continues in California, Idaho, Montana, Oregon and Washington.” US Agriculture Secretary Tom Vilsack said if current conditions persist, an average $200 million a week will be needed to battle the flames which have killed seven firefighters and overstretched resources. Officials fear further devastation in the coming months, especially in southern California, which experiences severe wind storms in the fall known as the Santa Ana winds. “September and October are generally when we see our worst wildfires,” said Lynne Tolmachoff, spokeswoman for Calfire, a monitoring agency. “The potential for a record year is definitely there,” she added. “We are still in a very severe drought with potential for very severe fire behaviour.” California is into its fourth year of a record-breaking drought that has parched much of the state and forced residents to cut back on water consumption and rethink their habits. Experts say that climate change is likely contributing to the increased frequency in infernos with some scientists predicting that by the end of the century megafires will become the norm.