Kostunica told the parliament that Serbia must not allow a state to be formed within a state that would break off part of Serbian territory.
All 226 lawmakers voted in support of the report, with no abstentions.
Kostunica sharply criticized international officials over statements which he said were prejudging independence as the outcome of UN-backed talks on the final status of Kosovo.
He repeated that Belgrade is offering Kosovo a "comprehensive autonomy," warning that independence as an "imposed solution" would sow the seed for a spiral of violent changes of borders on the same principle as with Kosovo.
(dpa)