Updated

The U.N. says a face-to-face encounter between Syria's government and the Western-backed opposition hoping to overthrow it is not going to happen as planned.

Friday was intended to be the first time since the uprising against Bashar Assad began that the two sides would sit down for direct negotiations — peace talks that have been on the verge of falling apart since they were first floated in 2012.

U.N. mediator Lakhdar Brahimi is meeting Friday morning with representatives of Assad and will meet later in the afternoon with a delegation from the Syrian National Coalition, said Alessandra Vellucci, a U.N. spokeswoman. She did not rule out direct talks later.

Assad adviser Bouthaina Shaaban blamed the opposition, saying her delegation is willing to negotiate.