Obama says coming weeks ‘critical’ for Syria’s future ahead of truce

US President Barack Obama on Thursday expressed confidence that the United States would prevail in its fight against the Islamic State, but said that an end to the conflict in Syria would be key to dismantling the group.

All combatants except the Islamic State group, Syria’s al-Qaida branch known as the Nusra Front and any other militia designated as a terrorist organization by the U.N. Security Council.

Decrying Russian President Vladimir Putin’s insertion of military forces into the conflict, which are aiding Moscow ally Assad, Obama again demanded that the Syrian leader relinquish power in order for peace to return to Syria.

Barack Obama has said maintaining the deal would depend on a number of factors: “Humanitarian aid must be allowed to reach areas under siege”.

Meanwhile, Turkey’s Foreign Minister Mevlut Cavusoglu told state-run Anadolu Agency that Saudi aircraft would arrive “today or tomorrow” at the Incirlik Air Base in southern Turkey to join the fight against Islamic State in Syria.

The United Nations will set a date for Syria’s warring parties to return to the negotiating table for a second round of talks on Friday, UN Syria envoy Staffan de Mistura says.

“That’s why the United States will do everything we can to maximize the chances of success in this cessation of hostilities”, he said.

The joint draft resolution, which diplomats say the 15-nation council plans to put to a vote on Friday afternoon, would endorse the halt in fighting and demand that it begin as planned at midnight local time on Saturday morning.

De Mistura abruptly aborted a first round of talks on February 3 and urged countries in the International Syria Support Group (ISSG), led by the United States and Russian Federation, to do more preparatory work.

This may quickly derail the deal, as the opposition and its supporters have already said they are concerned the Syrian government and Russian Federation will continue to strike at mainstream rebels under the pretext of hitting Nusra during the cease-fire.

Obama said he was not “under any illusions” about possible pitfalls, but said the ceasefire could be a “potential step in bringing about an end to the chaos”. The 5-year-old war in Syria has killed about 470,000 people and displaced 11 million, creating a refugee crisis in Europe.

“There’s no alternative to a managed transition away from Assad”.

“The world will be watching”, Obama said.

Obama said militants in Syria will never stop fighting until Assad is ousted from power.