Firefighters in Texas faced rising temperatures, strong winds and dry air in their battle to keep the largest wildfire in state history from turning more of the Panhandle into a parched wasteland.

Firefighters were focused on containing the fire along its northern and eastern perimeter, where gusts from the south west threatened to spread the flames and consume more acreage, according to Jason Nedlo, a spokesperson with the team of firefighters battling the Smokehouse Creek Fire.

“The main goal is to continue using dozers and fire engines to contain and patrol the fire,” Mr Nedlo said. “We’re also focused on not losing any more structures, no more loss of life.”

The massive fire has left a charred landscape of scorched prairie and dead cattle, and destroyed as many as 500 structures, including homes, in the Texas Panhandle.

It has merged with another fire and crossed the state line into Oklahoma, burning more than 1,700 square miles and was 15% contained, the Texas A&M Forest Service said on Saturday.

The National Weather Service issued a red flag warning for the entire Panhandle through to midnight on Sunday after rain and snow on Thursday allowed firefighters to contain a portion of the fire.

Signs warning travelers of the critical fire danger are in place along Interstate 40 leading into Amarillo.

Winds gusts of up to 45mph are expected on Saturday with humidity below 10% and a high temperature of 24C.

“New fires could also potentially start… the relative humidities are very low, the wind gusts are high and so it doesn’t take much, all there needs to be is a spark” to ignite another fire, said meteorologist William Churchill with the National Weather Prediction Centre.

Mr Nedlo said because of the ongoing weather conditions, it is not possible yet to predict when the flames will be fully contained and brought under control.

“We’ll know more after the weekend … we’re just not willing to speculate,” Mr Nedlo said.

The cause of the fire remains under investigation, although strong winds, dry grass and unseasonably warm weather fed the flames.

“Everybody needs to understand that we face enormous potential fire dangers as we head into this weekend,” Republican Governor Greg Abbott said on Friday after touring the area. “No one can let down their guard. Everyone must remain very vigilant.”

Two women were confirmed killed by the fires this week.

Two firefighters were injured battling the flames in Oklahoma. One suffered a heat-related injury and the other was injured when the brush pumper he was riding in struck a tanker truck as the two were heading to fight the fire near Gage.

Both firefighters are expected to recover.