回复：xiaobaitu,我听说规则变了，以前美国人去这些地儿不要护照

For foreigners, there is no change.
You can use I-94 to get in, same as Canada/Mexico travel. (with a few limitation, of course)
The change only applies to US citizen & PRs. They used to be able to travel without passport. Not after 2007.
However, foreigners always need to travel with passport.