Syrian opposition figures head to Moscow this week although they are unlikely to welcome Russia's plan for a new anti-ISIS coalition that would include embattled Syrian President Bashar al-Assad. Moscow has since June been pushing a plan for a broader grouping than the U.S.-led coalition fighting the ISIS group, to include Syria's government and its allies. But the initiative faces an uphill struggle given Assad's pariah status in the West and much of the Middle East. A first round of talks in the Russian capital on Tuesday with Saudi Foreign Minister Adel al-Jubeir ended with the Arab diplomat publicly ruling out such a coalition. "As for a coalition in which Saudi Arabia would participate with the government of Syria, then we need to exclude that. It is not part of our plans," he said. He added that Saudi, a key backer of Syria's opposition along with Turkey and Qatar, considered Assad part of the problem and that there would be no place for him in Syria's future. Moscow is unlikely to receive a warmer response from Syria's National Coalition, the main opposition political body. The group is sending a delegation headed by its president Khaled Khoja, scheduled to arrive on Thursday, for its first talks in Moscow since February 2014. Ahead of the meetings, Coalition member Hisham Marwa rejected any alliance involving Assad. "Confronting terrorism requires a transitional body that brings together all Syrians," he said. "It is clear that Assad and the criminals around him have no place in this phase, or in the future of Syria." Pushing UN envoy's plan A newer grouping of opposition figures, known as the Cairo Conference Committee, was also sceptical. "Victory against ISIL will come with political change in Syria that will unify all Syrian forces," said Haytham Manna, a leader of the group. He said his grouping would instead advocate for Russia to support a proposal put forward by the UN envoy on the Syria crisis, Staffan de Mistura. The proposal suggests the creation of four committees including regime and opposition figures to discuss security, political questions, military affairs and reconstruction. Topics to be covered would include ending sieges, medical access, freeing prisoners, holding elections, creating a transitional government, the fight against ISIS, and an eventual ceasefire. Syria's government, meanwhile, backs a separate plan that would form a transitional government made of regime and opposition figures and headed by Assad, with legislative elections in autumn, and constitutional reforms to define the powers of the president and government. "It would be a process that could last several years, for all of the mandate of Bashar al-Assad, which lasts until 2021," a Syrian political figure said. Moscow is also inviting Saleh Muslim, head of the Syrian Kurdish Democratic Union Party (PYD), in a sign of the growing complexity of the country's conflict. The PYD's armed wing controls large swathes of Kurdish-majority territory in northern Syria and has emerged as a key force fighting ISIS with help from the U.S.-led coalition.