In a video posted the fire fighters can be seen welcomed with applause and cheering.
The video tweeted by Shane Fitzsimmons, commissioner of the New South Wales Rural Fire Service, shows the firefighters arriving at Sydney International Airport to a cheering crowd of locals.
"US fire fighters arrived at Sydney Int Airport this week, on their way to assist with fire fighting in Victoria," Fitzsimmons wrote.
"Coming through, all gathered gave a spontaneous & lengthy round of applause, reflecting the gratitude & admiration we all have for their generosity."
As the video get viral on the social media, it gets applauded by the Tweeple.
An user wrote, "All looked very humble and ready to get down to business. I am glad there are some that can still carry on the compassionate side of the US people and not just represent the destruction we've come to symbolize."
A post read, "Now, see, this is America at its greatest, as well as basic common humanity. Bravo!"
"I'm so proud of US Firefighters. Austral greeting them shows how grateful they are. My heart aches for Australia. May God protect them all", added another.
Another user remarked, "Thank you to them and thank you so much to you too. Can only imagine how exhausted you must be. We appreciate everything you are doing."
Australia's bushfires this season have killed at least 27 people and damaged hundreds of homes, and the worst may yet to come. Alongside the career firefighters, there are thousands of volunteers who are fighting the flames.
( With inputs from IANS )