Syria’s main opposition coalition said Monday that it is willing to attend peace talks slated for later this year but laid out conditions that are likely to remain major stumbling blocks to bringing both sides to the table.

Although the Syrian Opposition Coalition’s announcement was hailed by Secretary of State John F. Kerry as an important step, one of its demands is that President Bashar al-Assad not play any role in a transitional government. That remains starkly at odds with the Syrian government’s position, which rejects any preconditions.

The United States, the United Nations and Russia have been pushing for negotiations for months, but progress has been slow and diplomats are scrambling to bring together the Geneva talks, first slated for early this past summer, by the end of the year.

The coalition also demanded the release of political prisoners and the easing of tight blockades on rebel-held areas.

The substance of the statement, voted on early Monday by a majority of the fractious body, is not new but gives the opposition an official and unified position ahead of talks, relieving pressure from the international community.

The announcement does mark a slight softening from last month, when coalition leader Ahmad al-Jarba said the group would boycott the talks if Assad supporter Iran attended or if there were no specific time frame for Assad to leave office.

Despite the unified position, the meeting was beset by familiar internal disputes amid claims from attendees that Jarba slapped Louay al-Mokdad, a representative for the Free Syrian Army, during a dispute about representation. In a video posted online Monday, Mokdad confirmed that he had had an “altercation” with the coalition leader, likening Jarba’s actions with that of Assad’s shabiha militia. A spokeswoman for the coalition declined to comment.

The opposition had shown some reluctance to commit to the talks, angered by a lack of U.S. military support for rebels and the Obama administration’s decision to hold off on punitive strikes that it initially pledged after an Aug. 21 chemical attack in the Damascus suburbs. The coalition also complained that a subsequent agreement for Syria to destroy its chemical weapons only distracts the international community as Assad continues to use the conventional arms, missiles and air power that have killed the vast majority of the more than 100,000 war dead.

Speaking to reporters in Abu Dhabi, in the United Arab Emirates, Kerry hailed the opposition decision as a “big step forward and an important one,” the Associated Press reported. British Foreign Secretary William Hague said that in light of the statement, he would put forward a proposal to the British Parliament to increase support to the opposition through medical, logistical and communication equipment for the Syrian opposition ahead of talks.

However, disagreements between the two sides over Assad’s role in a transition appear irreconcilable.

Syrian Information Minister Omran al-Zoubi said last week that the government will not go to Geneva with the intention of handing over power or forming a transitional governing body, and that Assad would remain head of state, according to the state-run Syrian Arab News Agency. Assad has repeatedly said that it is up to the Syrian people to decide his fate, while hinting that he might run for reelection next year. He has also repeatedly stressed that he will not negotiate with “terrorists,” which is how the government describes any armed opposition.

The opposition’s demands echo a communique released by the “London 11” in the British capital last month, in which foreign ministers from 11 countries that support the Syrian opposition, including the United States, Britain, Turkey and Saudi Arabia, said there was “no role” for Assad or his close associates in a transitional body.

“There can be no peaceful settlement to the conflict in Syria without a strong role for the legitimate, moderate opposition,” Hague told the House of Commons on Monday. He said the opposition was right to demand access for aid agencies, where hopes have been raised in recent weeks after several negotiations to lift blockades.

Thousands of civilians have been evacuated from the rebel-held area of Moadamiya over the past month. Field doctors in the suburb west of Damascus had said women and children were dying of starvation as troops prevented food or supplies from entering. Activists also said supplies were allowed into the town of Qudsaya, near the Syrian capital, on Sunday for the first time in weeks.