Vietnamese authorities are now allowing access to the Long Tan cross for today's anniversary commemorations, but the main ceremony will not go ahead.

The Australian Government said this morning Hanoi was now allowing travel to the area but under very strict conditions, including travelling in small groups staggered throughout the day and a media ban.

The main commemoration ceremony at 3.30pm remained cancelled.

The Battle of Long Tan was one of the bloodiest fought by Australian and Kiwi troops during the Vietnam War.

Memorial events have been held at Long Tan, about 100km east of Ho Chi Minh City, since 1989. Veterans had spent 18 months planning this year's 50th anniversary of the battle.