PICTURED: Behind the scenes of Avatar sequels where Kate Winslet reunites with Titanic director James Cameron trained to 'hold her breath for nearly seven minutes underwater' after cast had to learn to free dive for grueling scenes in 900,000-gallon tank

20th Century Fox have released new behind-the-scenes photos from the set of the Avatar sequels. 

The pictures, posted Friday to the official Avatar Twitter account, were taken earlier this year on set in New Zealand. Filming for the sequels is currently on hold due to the coronavirus outbreak, although visual production work is still continuing in Manhattan Beach, California. 

Avatar 2 and 3 are being filmed at the same time and have a combined budget of $500 million. Despite the COVID-19 outbreak, Avatar 2 is still scheduled to hit cinemas in December 2021.  The third film is due for release in 2023.   

The movies will largely be set underwater, and much of the filming has taken place in a gigantic 900,000-gallon water tank. 

One new behind-the-scenes snap shows stars Sam Worthington, Kate Winslet, Zoe Saldana and Cliff Curtis floating in the tank during a break from filming in New Zealand.

The cast are expected to swim and dive beneath the surface as camera crews capture their performance.