St John New Zealand has announced that Z Energy has given the charity a month of free fuel to help "through this tough time".
St John made the announcement on Facebook and added an appeal for Kiwis to stay home.
The free fuel will help keep 700 ambulances and operation vechiles on the road throughout the alert level 4 period.
"Seven hundred ambulances and operational vehicles will be on the road during this lockdown," the post said.
"While we save lives, we ask that you to continue to #stayhome, #bekind and #breakthechain of Covid-19 transmission."
Kiwis on Facebook expressed their gratitude and were impressed to see companies helping those who need them.
"Truly an awesome inspiration. So good when companies step up and take the lead to keep important things going," a Facebook user said.
"What a thoughtful gesture. Thank you for allowing Z shareholders to be part of this and making them proud," another person said.
• Covid19.govt.nz: The Government's official Covid-19 advisory website