As with the first film it's the international totals that will secure a sequel if we get one. Internationally PRU did $185 million which is better than the first film even with adding the China opening which was weeks later for the first film ($185 vs. $166 million ($88 plus $78 million)). The $185 million is also 60% of the first film international total of $309 million.
The biggest variable is how other films being released will affect PRU going forward, Ready Player One has already hurt the film (opening at $53 million) and Rampage will almost certain effect it since both films will pull from the same group of fans. Avengers Infinity War will most likely pull most remaining film goers away since it's in the same action adventure genre and already looks to be massive (base on ticket pre-sales), PRU will need to get most of it's box office take before than.
Steven S DeKnight has said he has an plan for Pacific Rim going forward (assumingly with Guillermo del Toro's blessing), hopefully we'll get to see it, since more kaiju films the better it is for fans.