The US has seen a harsh wildfire season this year, with prolonged droughts and dry conditions fuelling blazes.

Three firefighters have died while responding to wildfires in the western United States, according to the US Wildland Fire Service.

In a statement on Sunday, the agency said the firefighters had been responding to the Knowles and Gore fires along the Utah-Colorado border.

The agency, which was created earlier this year to streamline firefighting and fire reduction across public lands, said it stands “in grief and in our unwavering support for the loved ones left behind”.

It said two crew members were also injured while responding to the fires, adding that more details would be released shortly.

The deaths come amid a particularly harsh wildfire season in the US, with consecutive days of hot, dry and windy weather fuelling flames across the western reaches of the country.

Nationwide, nearly three million acres (1.2 million hectares) have burned since the start of the year, surpassing the 10-year average.

At least three dozen wildfires burning in the US as of Sunday were classified as “uncontained”, according to authorities.

Over the last week, the governors of both Utah and Colorado declared state emergencies.

The move allowed Utah’s Governor, Spencer Cox, to ban fireworks ahead of the 4th of July holiday.

“Today, we mourn three heroes who made the ultimate sacrifice protecting lives and communities along the Utah-Colorado border,” Cox said in a post on Sunday.

The state government, meanwhile, warned that persistent drought and dry conditions continued to create “above-normal wildfire potential”.

Colorado Governor, Jared Polis, declared an emergency on Saturday, authorising the use of the National Guard to tackle the fires.

Arizona has also been particularly hard-hit recently, with wildfires burning south of the Grand Canyon and near Kendrick Mountain.

Parts of northern Arizona were without power on Saturday as the utility serving the area initiated a safety shut-off hoping to reduce the risk of wildfires.

The US National Oceanic and Atmospheric Administration has said that climate change has increased the chances of wildfires in recent years, causing high temperatures, extended droughts and dry conditions that fuel fires.

The western blazes come as Europe has contended with a record heatwave, which is expected to hit the eastern US on Wednesday.