After a dour handshake, barbed remarks over Syria and a toast that was anything but toasty, U.S. President Barack Obama and his Russian counterpart, Vladimir Putin, began their first formal discussions in two years Monday at the U.N.
Neither leader showed much warmth in a formal handshake for the cameras at the summit meeting at the U.N. General Assembly. And Obama pointedly refused to return Putin's smile during a toast at dinner, remaining grim-looking and stone-faced.
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Even the main topic of their talks is disputed: The U.S. says they're about Russia's intervention in eastern Ukraine, while Russia insists they're about Syria, where it has built up forces in recent weeks in support of President Bashar al-Assad.
But both men's remarks before their meeting made it clear that Syria is the main point of contention. Obama assailed Syrian President Bashar Assad, saying he must relinquish power, while Putin supported Assad up as the only option to defeat ISIS.
Obama called Assad a "tyrant" who "drops barrel bombs to massacre innocent civilians."
While ISIS — which he called an "apocalyptic cult" — must be defeated, Obama said, "dangerous currents risk pulling us back into a darker, more disordered world."
The media pool reporter relaying the event noted that members of the Russian delegation could be seen shaking their heads in disagreement during Obama's remarks.
When his turn came, Putin defended Assad as a stabilizing force who's "valiantly fighting terrorism face to face."
"This is not about Russia's ambitions but about the recognition of the fact that we can no longer tolerate the urgent state of affairs in the world," he said.
White House officials said that during their one-on-one meeting, Obama would push Putin to explain how Russia's presence in Syria could help defeat ISIS.
And they said Obama would make time to discuss the crisis in Ukraine, which Obama said in his address could not be allowed to fall under Russian rule.
"If that happens without consequences in Ukraine, it could happen to any nation gathered here today," Obama said.
This article first appeared at NBCNews.com