A/HRC/37/72 ceasefire negotiated between Faylaq al-Rahman, Jaysh al-Islam and the Russian Federation in July and August. 31. Russian and Syrian forces escalated aerial operations in early October 2017 on Idlib and Hamah after Hay’at Tahrir al-Sham opened an offensive against Government positions in northern Hamah. The campaign focused on the remaining opposition pockets in Idlib and north-eastern Hamah as well as on retaking strategic infrastructure such as the Abu Duhur airbase (see para. 76). Turkish troops concurrently moved into Idlib as part of an operation to enforce a de-escalation zone, while simultaneously shelling Hay’at Tahrir al-Sham positions in support of a Free Syrian Army advance. In the central part of the country, after a four-month long military campaign, Syrian Democratic Forces declared Raqqah liberated from ISIL on 20 October 2017, and established a civil council to administer the city. 32. Military campaigns accelerated throughout November 2017, with the Syrian Army scoring major victories in the south, and declaring on 3 November that it had taken full control over the city of Dayr al-Zawr. In the north-west, Hay’at Tahrir al-Sham continued to lose its military sway after the defection of two large components — Nour al-Din alZenki and Jaysh al-Ahrar. The defections created hostilities between Hay’at Tahrir al-Sham and Nour al-Din al-Zenki and triggered violent clashes in western Aleppo. In an attempt to end the clashes, both groups signed an agreement in mid-November, which resulted in an immediate cessation of hostilities. 33. On the diplomatic front, the presidents of the United States and the Russian Federation signed a statement on 11 November 2017 at the Asia-Pacific Economic Cooperation summit in Vietnam, highlighting the need for a constitutional reform process and the scheduling of United Nations-supervised elections in the Syrian Arab Republic. On 21 November, a day before the beginning of the Turkish-Iranian-Russian tripartite summit on the Syrian Arab Republic, President Putin and President al-Assad agreed that the military operation in the Syrian Arab Republic was coming to an end and they emphasized the need to launch a political process that would encompass a Syrian national dialogue congress to be held in Sochi, Russian Federation. With diverging Russian and American opinions over the future role of United States troops in northern Syria, Kurdish aspirations for self-determination as well as efforts to reach a political settlement in Sochi will remain contentious issues and no doubt impact efforts to build international consensus on the political settlement to the crisis. Saudi Arabia also endeavoured to shape the peace process by hosting a meeting in Riyadh, from 22 to 24 November, aimed at forming a joint delegation that would represent different factions of the Syrian opposition at the next round of Geneva peace talks. At the end of the meeting, the Syrian opposition issued the Riyadh II declaration, in which it announced the creation of a 50-member body to participate in the Geneva talks and engage in direct negotiations with the Government, without preconditions. 34. On 28 November, the Special Envoy of the Secretary-General for Syria, Staffan de Mistura, opened the eighth round of intra-Syrian peace talks in Geneva, which focused on the constitutional process and the scheduling of United Nations-supervised elections in the context of implementing Security Council resolution 2254 (2015). The delegation of the Government of the Syrian Arab Republic postponed its departure for the talks following the publication of the Riyadh II statement, which, according to the Government, contains a precondition for President al-Assad to leave the country. Although the Special Envoy extended the talks until 15 December, the goal of holding direct talks between the Government and the opposition was not achieved. 35. On 11 December 2017, President Putin visited Humaymim airbase (Ladhiqiyah) to announce the withdrawal of a significant part of the contingent of Russian troops following the declaration by the Chief of Staff of the Russian Armed Forces that the country has been completely liberated from ISIL. On 21 and 22 December, the Government of Kazakhstan hosted the eighth round of the Astana talks, which focused on the situation in the deescalation zones and the issue of releasing detainees. At the end of the meeting, the guarantor States issued a joint statement announcing the beginning of preparations for the Syrian National Dialogue Congress to be held in Sochi on 29 and 30 January 2018. In response, more than 40 opposition groups called for a boycott of the Sochi congress, 8