Vietnamese authorities have agreed to allow restricted access to the Long Tan site after negotiations with the Australian Government overnight.

Key points: Vietnam is allowing access to groups of 100 people or fewer

Vietnam is allowing access to groups of 100 people or fewer A planned gala dinner and concert deemed insensitive

A planned gala dinner and concert deemed insensitive More than 1,000 Australians have travelled to Vietnam for the anniversary

More than 1,000 Australians have travelled to Vietnam for the anniversary Veterans disgruntled over inability to visit site

Access to the site is being limited to groups of 100 people or fewer.

There will also be a wreath laying in the afternoon, which 1,000 people will be able to attend.

A Vietnamese Government source told the ABC the Australian Consulate had promised to hold a "low key" event, but that a planned gala dinner and concert were seen as insensitive.

Visitors to the Battle of Long Tan site are not allowed to wear medals or uniforms, carry banners or make speeches.

The commemoration ceremony to mark the 50th anniversary remains cancelled.

Loading

Veterans' Affairs Minister Dan Tehan, who yesterday described the last-minute cancellation as "a kick in the guts", said he was glad for the reprieve.

"The Prime Minister appealed to the Vietnamese Prime Minister to understand and empathise with the Australian veterans and their families who have travelled to Vietnam," he said.

"We understand there are still sensitivities in Vietnam, so over the last 18 months, we have said that we would respect how they would like us to commemorate.

"We are very grateful for the Vietnamese change of mind on this."

Mr Tehan said more than 1,000 Australians had travelled to Vietnam to mark the anniversary.

Veterans 'still suffering' 50 years on

Vietnam Veterans Association of Australia president Ken Foster said the reversal would not change damage done to veterans who had travelled to Vietnam for the anniversary.

"It's still left a very damaging effect, in some cases, to the emotions of veterans that are always sensitive at this time of year," he said.

"Quite a few Vietnam vets, 50 years down the track, are still suffering emotionally.

"The mood has been soured somewhat."

Veteran Bill Crowly was among those to travel to Vietnam.

"I'm really saddened by that actually, because I really came over because of the anniversary," he said.

"I thought if I didn't come back now, I would never come back."

Loading

West Australian Vietnam veteran Peter Manucci and his tour group of "Vietnam gunners" were refused entry to the battlefield on Wednesday.

"I am pretty well pissed off," he said.

"There is 3,500 people who are booked in to go the Long Tan Cross and that's why they are not happy.

Mr Manucci said each visitor paid about $12 in advance to see the site.

"They have our money ... that's $30,000 in their pocket, gone, thank you very much," he said.

Concert cancellation 'big disappointment' for Little Pattie

At 17, Little Pattie was the youngest performer to go to war. ( Supplied: Patricia Amphlett )

The planned concert was to feature Australian singer Patricia Amphlett, better known as Little Pattie, who was performing for the troops as the Battle of Long Tan began.

"This is the biggest disappointment," Amphlett told Australian Story.

"We couldn't even get a third of a way through our rehearsal this afternoon. We were told we had 20 minutes to get out before the police arrived."

Loading

The Long Tan anniversary is a contentious topic in Vietnam. Small groups are allowed to visit but are not allowed to wear medals or uniforms, or play songs.

In recent years, the playing of The Last Post has been allowed.

According to the Department of Veterans' Affairs, 18 Australians were killed in the Battle of Long Tan, with another 24 wounded.

Australian forces counted 245 dead Vietnamese.