Beirut: One of the major opposition blocs in the Syrian war said on Wednesday that it was unlikely to attend imminent Geneva peace talks, specifying it would only join negotiations if sieges in the country are lifted and other conditions are met.

The announcement cast further uncertainty on peace talks scheduled to begin in two days.

Expectations are already low for any breakthroughs during talks that UN envoy Staffan de Mistura has described as the start of a drawn-out process of consultation between various parties to the conflict, rather than actual peace negotiations between the warring sides.

Khalid Nasser, a member of the Syrian National Coalition — one of the main opposition groups in the bloc — said on Wednesday that he believed negotiations with limited ambitions would “waste time.”

“Friday was never going to be the start of negotiations,” said Nasser. “De Mistura said it is for consultations and discussions ... We don’t want to waste time with consultations and discussions.”

The talks are intended to start a political process to end the conflict that began in 2011 as a largely peaceful uprising against Syrian President Bashar Al Assad’s rule but escalated into an all-out war after a harsh state crackdown. The plan calls for ceasefires in parallel to the talks, a new constitution and elections in a year and a half.

In a sign of the complexity of the task, de Mistura said the delegations in Geneva would be sitting in separate rooms and he would shuttle between them to begin with.

There have also been major tensions over who would be invited to the talks, and the opposition has demanded confidence-building measures from the government on humanitarian issues.

In a statement released at the end of daylong meetings in Saudi Arabia late on Tuesday, the opposition coalition known as the Higher Negotiating Committee referred to the “necessity of realising genuine improvements on the ground before starting in the negotiating process.”

The Saudi-backed committee is headed by Riad Hijab, a former prime minister who defected to the opposition in 2012. It represents a bloc that includes the Syrian National Coalition, and many of the major rebel factions fighting in Syria.

As well as the public statement released on Tuesday, the bloc outlined its conditions for participating in the talks in a letter to UN chief Ban Ki-moon. While the group left open the possibility of its eventual participation in the talks scheduled to begin on Friday, it said it awaits a reply from him on its conditions.

The opposition has also accused Russia, a key backer of the Syrian government, of trying to “dictate” who from the opposition would participate.

Moscow has insisted on the participation of the main Syrian Kurdish group — the Democratic Union Party, or PYD — which plays an important role in fighting the Daesh group and is an essential part of any political settlement in Syria.

Turkey, a major backer of the rebels, sees the PYD and its YPG militia as branches of the Kurdistan Workers’ Party, known as the PKK, which has waged a long insurgency against Ankara. Turkey has threatened to boycott the talks if the PYD is represented.

French Foreign Minister Laurent Fabius told France-Culture radio on Wednesday that the PYD was not invited and acknowledged there are several hurdles facing the talks, including determining who will be present.

“The PYD group, the Kurdish group, was causing the most problems, and Mr. de Mistura told me he had not sent them an invitation letter,” Fabius said.

He said the Riyadh-backed Higher Negotiating Committee should be the primary negotiator for the rebels.

The Riyadh bloc is a broad coalition that includes several armed Islamist groups, such as the powerful Jaish Al Islam, which the Russian and Syrian governments consider as a terrorist group. It does not, however, include the Daesh group or Al Nusra Front, two militant factions that control large areas of Syria and are not participating in peace talks.