This is where the distinction between restrictive and nonrestrictive clauses comes into picture.
The proper way to write 1) is:
Alaska is one of the states of America which/that is located on the border side.
Note the absence of comma above: the restrictive relative clause which/that is located on the border side is essential, because it provides necessary information about Alaska.
Likewise, 2) should be written as:
Alaska is one of the states of America, which is a superpower country.
Here you need a comma after America, and the following nonrestrictive relative clause which is a superpower merely adds extra information about America. You could do away with this parenthetical part. Note also that in this case you must only use which.