The television network will report live from inside one of the world's most beautiful caves in the central province of Quang Binh. The exact location is being kept a secret until filming is finished.

About six million subscribers will watch this programme, which is due to live air on May 13, from 6am American time (6pm Vietnamese time).

Viewers in Viet Nam will not be able to watch the show live, but can still enjoy its re-broadcast on ABC’s website, at abc.go.com.

The American broadcaster last month signed an agreement with local authorities to feature the Southeast Asian country's beauty spots in its high rating Good Morning America show.

To prepare for the programme, ABC sent a 12-person crew and more than a tonne of specialised equipment to Viet Nam.

A 32-second trailer of the programme was screened online last week, drawing many viewers.

Maria Stefanopoulos, a production manager at ABC News, Good Morning America, told Tuoi Tre reporters that after watching the trailer, many viewers thought that the programme was featuring amazing landscapes from Hawaii, not Viet Nam.

Meanwhile, Romeo Durscher, a crew member, who is also director of education at DJI, a well-known drone camera producer, said only two hours after the launch of the trailer, he got many requests from travel magazines for stories and photographs.

Durscher, who is in charge of the crew's drone camera operation, said the programme would use a total of seven modern flycams to take aerial shots.

In April, he and other ABC technicians inspected the cave and conducted trial camera work, which turned out well.

Alongside an American crew of 12, another 120 people have arrived at the cave to contribute to the show's production.

While some equipment has been transported to the venue by road, bulky goods have been flown in by helicopter.

Ginger Zee, the host of Good Morning America and ABC World News Tonight, will appear on the Viet Nam show.

"It's a great honour for me to be selected as the host of ABC's first-ever live programme shot from inside a grotto in Viet Nam," Zee told Tuoi Tre.

On Saturday morning, the last members of the programme's crew headed for the cave.

Its exact location is being kept a secret from the public until filming is completed.

Crew members have been asked not to upload any snapshots taken during the trip onto social networks or reveal the filming location.

The programme will also feature images of Viet Nam, including Ha Long Bay and the Son River which meanders in Quang Binh Province.