Saudi foreign minister: Putin's rationale in Syria "inconceivable"

Hundreds of world leaders gathered Tuesday for a United Nations summit, where they addressed the fight against the Islamic State of Iraq and Syria (ISIS) (called "Daesh" in the Arab world) and the war in Syria.

In an exclusive interview with"CBS This Morning"co-host Norah O'Donnell, Foreign Minister Adel al-Jubeir of Saudi Arabia -- which is a member of an international coalition to fight ISIS in Syria -- shared his views on those key issues.

Al-Jubier said that while he doubted "any of the members would mind" if Russia wanted to be part of the coalition, he viewed Russia's assessment of "what's doable and not doable in Syria" as incorrect.

"So the question that it begs is why would they go to Syria unilaterally to fight Daesh when there is an international coalition in place fighting Daesh as we speak," al-Jubeir said. "I believe it's to support Bashar al-Assad."

Saudi FM on accuracy of airstrikes in Yemen, civilian casualties

In a recent "60 Minutes" interview with co-host Charlie Rose, Russian President Vladimir Putin said that while Russia was not planning on participating in any troop operations in Syria, it was "considering intensifying our work with both President Assad and with our partners in other countries."

But al-Jubeir said that prospect was "inconceivable."

"They're proposing a coalition with Assad to fight against Daesh in Syria. He was the person who created them," al-Jubeir said. "And after Daesh is defeated in Syria, we can talk about a colatish-- a transition in Syria. A coalition with Assad is inconceivable."

When asked if Saudi Arabia--which is carrying out airstrikes against ISIS targets in Syria with the U.S.--would consider putting its troops on the ground, al-Jubeir said, "With regards to any other issues, I think we have to consider all the options and see and do a cost-benefit analysis."

But the foreign minister acknowledged that Syria needs "more robust intervention," particularly with ending Bashar al-Assad's leadership.

"I believe the world has to be more firm in insisting that Bashar leave. If he wants to leave through a political process it would be preferable," he said.