Trying to find Military Sci Fi movie?

[heather]

I'm trying to find a sci fi movie, it US military in a foreign country, I think somewhere in South America, and they were fighting against this thing, pretty sure it was supposed to have been engineered by the military and it could absorb people and take their shape, but if the thing got hit or hurt at all it would revert back to this energy type blobby thing. The last scene after the hero destroyed it was the guy in the field meeting this local woman and then slapping her to find out if she was the creature or not, ended up with her chasing him across the field. Also I think the movie came out late 90s early 2000s. Thanks