Aquaman and the Lost Kingdom, the sequel to DC's highest-grossing film, will be released across the Chinese mainland on Dec 20, two days earlier than in North America.

Director James Wan recently returned to Beijing, five years after his first visit to promote Aquaman, which earned 2.01 billion yuan ($281.4 million) in 2018.

Picking up from the end of the first installment, the new movie finds the protagonist superhero Arthur Curry, the ruler of the underwater kingdom of Atlantis who is also going by the alias of Aquaman, reuniting with his half brother Orm, who was once hostile toward him. Together, they will fight their enemy, Black Manta, who has unleashed a devastating weapon in his obsessive quest to avenge his father's death.

American actor Jason Momoa, who reprises his role as Aquaman, revealed during a Beijing promotional event on Wednesday that his character will undergo a significant change in the new film.

The character is not just the king of the underwater world but will also shoulder his responsibilities as a new father and husband, said Momoa.