"It is completely ridiculous and delusive to believe that there is a possibility of creating a vacuum in the leadership in Syria," Iranian Foreign Minister Ali Akbar Salehi said. "We call upon the people of the region to be fully aware and not to move in the wrong direction, because there will be severe consequences that will go beyond the borders of the region to the outside world."

The Syrian crisis started in March 2011, after al-Assad's regime cracked down on peaceful protests.

More than 20,000 people, mostly civilians, have died in the conflict, the LCC said. Last week, U.N. Secretary-General Ban Ki-moon said almost 17,000 people have died.