'Avatar: The Way of Water' crossed $1 billion, halfway to the mark James Cameron said it needed to break even. It will have to overcome 2 hurdles to do it.

• "Avatar: The Way of Water" has grossed over $1 billion at the global box office.
• But it may need to double that to reach the mark James Cameron has said it needs to break even.

"Avatar: The Way of Water" hit an important box-office milestone this week, crossing $1 billion at the global box office in two weeks.

But the sequel to the highest-grossing movie will need to overcome two key hurdles to double that number, a mark its director, James Cameron, suggested it would need to hit to be successful.

Cameron told GQ last month that "The Way of Water" would have to be "the third or fourth highest-grossing film in history" just to break even. No. 4 is "Star Wars: The Force Awakens," which grossed $2.07 billion.

If "The Way of Water" achieved that, it would put it in league with Cameron's own "Titanic," the No. 3 highest-grossing movie, and "Avatar," No. 1.

But one key market could decide that. The first "Avatar" was a smash hit in China, grossing about $262 million there, including a rerelease last year.

"The Way of Water" is off to a slow start in the region, grossing $104 million there after two weekends. It may face slumping ticket sales in the coming weeks as the country deals with rising coronavirus cases.

It's not just China where the movie needs to keep up momentum, though. The first "Avatar" was such a blockbuster because of its strong overall legs.

It opened with just $77 million in the US in 2009 but had small drops at the box office over the course of its months-long theatrical run. It declined just 2% in its second weekend and only 9.5% from that in its third. It ultimately grossed $785 million in the US alone.

Those kinds of slight drops are rare today, but "The Way of Water" still had a better hold in its second weekend than most recent blockbusters, falling 52% in its second weekend in the US.

Repeat viewing would help its momentum at the box office in the coming weeks. One exhibition source told Insider that the movie ranked below recent tentpoles, including Marvel movies, in repeat ticket sales and that it didn't appear to be a large driver of its box office so far.

But "The Way of Water" faces little competition until the next tentpole release, Marvel's "Ant-Man and the Wasp: Quantumania," in February and still has time to meet its high expectations.