Commemoration services are being held in Darwin today to remember those who lost their lives during Japanese air raids on the city during World War II.

It has been 71 years since Japanese forces launched air raids on the Top End, killing at least 243 people.

Darwin Military Museum director Tom Lewis says the defence of Darwin is now starting to gain the recognition it deserves after often being overlooked.

"We are slowly managing to bring it into public consciousness," he said.

Australian-American Association spokesman Rick Setter says the co-operation between the Australian and US forces in the defence of Darwin, was a pivotal point in the two nations' relationship.

"We have formed a very close relationship between our two peoples and also our military," he said.

Last year the anniversary of the bombing was made a National Day of Observance.