A military solution will ruin Syria as a state, he said, adding that there would be no winners in that war.
The diplomat warned against a repetition of the Libyan scenario on Syria.
He called for a halt to arms supplies to the conflicting parties and for broader international assistance to peace-promoting efforts.
On December 29, Mr. Brahimi is due in Moscow for talks with Foreign Minister Sergei Lavrov.
Voice of Russia, TASS, Interfax
A transition government with full executive powers should pave the way for peace in Syria, UN- Arab League envoy Lakhdar Brahimi has said.
“We need to form a government with all powers which will assume power during a period of transition,” Mr. Brahimi said at a press conference in Damascus.
The UN peace envoy stressed the transition government would then organize presidential elections in Syria.
International peace envoy Lakhdar Brahimi on Thursday called for "real" change in war-torn Syria and the installation of a transition government with full powers until elections can be held.
The UN-Arab League envoy made the remarks at a news conference in Damascus, during his latest bid to persuade Syria's warring parties to negotiate an end to the conflict estimated to have killed at least 45,000 people.
Voice of Russia, Interfax, AFP