Avatar: The Way of Water faces disappointing opening weekend at the box office, but experts say there's still a long way to go

Expectations were high for James Cameron's long-awaited and pricey sequel to 2009's Avatar.

But studio estimates show Avatar: The Way of Water made $US134 million ($199 million) in the United States and Canada in its opening weekend and $US300.5 million internationally, meaning it grossed $US434.5 million for its global debut.

"How can a $US134 million opening weekend be considered disappointing?" You may rightfully ask.