The announcement comes a day after the opposition insisted Assad must not have a role in a future transition, echoing repeated calls by Western powers for the president to step down.
The January 22 peace conference dubbed Geneva 2 is aimed at ending the nearly three-year-old civil war, a bloody stalemate which has killed an estimated 120,000 people and driven millions from their homes.
"Syria announces the participation of an official delegation under the orders of (Assad) and the demands of the Syrian people, with the top priority eliminating terrorism," a foreign ministry source said, quoted by the official SANA news agency.
"The official Syrian delegation will not go to Geneva to hand over power, but to take part (in talks) along with those who are committed to furthering the interests of the Syrian people and who support a political solution for Syria's future," the source said.
More From This Section
"Our people will not allow anyone to steal their right to choose their future and their leaders, and what is key about Geneva is to assert the Syrians' rights, and not of those who are spilling the people's blood."
"The ministry reminds them that the age of colonialism is over, and they need to wake up... Otherwise it will be useless for them to attend Geneva 2."
Yesterday, French Foreign Minister Laurent Fabius said the peace talks would take place in the Swiss city without the presence of Assad or his radical opponents.
His remarks came as the opposition National Coalition, an umbrella group increasingly at odds with rebels on the ground, insisted Assad must go, casting doubt on whether a compromise can be found.
But while the Coalition enjoys Western support, it is unclear how much control it has over the hundreds of rebel groups fighting on the ground.