Jetstar was to increase direct flights from Adelaide to Darwin from two to five each week, starting in July, the airline announced today.

The increase comes even before the first Jetstar flights into the Northern Territory take off in May.

The company previously said it would begin direct flights to Darwin from Melbourne, Brisbane and Adelaide from May 1.

But Jetstar said today it would fly from Adelaide to Darwin twice weekly for the just first two months and then increase services to five flights weekly from July 1.

Jetstar Chief Executive Alan Joyce said the extra flights reinforced the company's commitment to grow services into Darwin.

"Jetstar will continue to look for further growth opportunities in the Northern Territory, including the prospect of linking new domestic markets with Darwin, as well as exploring the commercial viability of future international services from the Northern Territory over the longer term," Mr Joyce said.

"Consumer demand for our soon-to-commence value flights to and from Darwin has been sound and is meeting expectations."