Syrian opposition chief Riad Hijab arrived in Switzerland on Wednesday afternoon, his grouping said, in a move that could rekindle troubled UN-brokered peace talks.

"Riad Hijab has arrived in Geneva," the High Negotiations Committee (HNC) said on its official Twitter account.

Hijab is expected to immediately join a tense internal HNC meeting in which the group will decide its next steps in the talks.

His arrival was seen as a potentially positive sign because of the weight he carries with the HNC, a Saudi-backed opposition alliance that is opposed to President Bashar al-Assad.

"With Hijab here, the HNC can better demonstrate a unified position in representing the opposition," a Western diplomat said in Geneva on condition of anonymity.

"This is a very complicated process and it's going to require all the actors to remain in constant dialogue," the diplomat said.