An all-star star lineup of world leaders was taking the stage at the United Nations on Monday, but all eyes will be on the sidelines for the first meeting between the estranged U.S. and Russian leaders in nearly a year.
President Barack Obama and his Moscow-based counterpart Vladimir Putin will come face-to-face at a time when relations between the U.S. and Russia have fallen to near Cold War-level lows amid disagreements over Syria and Ukraine.
The issues between the U.S. and Russia were evident well before Monday's meeting. The two countries were unable to agree on the premise of the meeting — the White House says that Putin reached out, which the Kremlin disputes — or even what the two leaders will discuss.
The White House initially said the talks would focus on Ukraine, while the Kremlin said Syria and the fight against ISIS would be at the fore. The Obama administration has since confirmed Syria will be on high on the agenda.
Related: Why Putin Won't Let Syria Go
Putin told "60 Minutes" on Sunday that he and Obama "listen to each other in a way," but when asked if the U.S. president considers him an equal said: "How could I know what he thinks?"
Before he gets to hear for himself, Putin got a chance to hear Obama address the world leaders gathered at the U.N. General Assembly in a stinging critique sure to set a tense tone for the talk.
The U.S. president called Assad a "tyrant" and said the world can't stand by while Russia violates Ukraine's integrity and sovereignty.
While Obama said the U.S. was willing to work with Russia as well as Iran to achieve a "managed transition" to remove Assad from power, he rejected Putin's continued support for the Syrian leader.
Later on Monday, Putin told the General Assembly that supporting Assad was the only way to curtail ISIS and stem the overwhelming flow of refugees.
"It would be a mistake not to cooperate with the Syrian government," Putin said.
The Russian leader made the same point in his interview with "60 Minutes," saying that "there is no other solution to the Syrian crisis than strengthening the effective government structures and rendering them help in fighting terrorism."
Putin said that Russia "will not participate in any troop operations" in Syria at the moment, but is looking into "intensifying" its work with Assad.
That work has been under a microscope of late: Russia's recent military buildup in Syria has flummoxed and concerned U.S. officials, who fear Moscow has been sending in weapons to shore up Assad.
Monday's meeting will give Obama an opportunity to ask Putin directly about Russian military forces in Syria — though few expect Moscow is interested in joining the U.S.-led anti-ISIS coalition.
“It's time for clarity and for Russia to come clean and come clear on just exactly how it proposes to be a constructive contributor to what is already an ongoing multi-nation coalition,” said Celeste Wallander, the White House National Security Council's senior director for Russia. “That's a question for President Putin, and it’s a question we’ll be posing to President Putin.”
"We're just at the beginning of trying to understand what the Russians intentions are in Syria, in Iraq, and to try and see if there are mutually beneficial ways forward here," a senior State Department Official said Sunday. "We've got a long way to go in that conversation."
Putin has insisted that Russia's presence in Syria was "under entirely legal international contracts," telling "60 Minutes" that it only has supplied weapons to the government, personnel training and humanitarian aid.
He also criticized U.S. efforts to train moderate opposition and suggested Washington was in violation of international law by supporting non-state structures.
Kerry struck a slightly more conciliatory note on Sunday, saying from New York that discussions with Russia were "the beginning of a genuine effort to see if there is a way to de-conflict, but also to find a way forward that will be effective in keeping a united, secular Syria that can be at peace and stable again."
However, U.S. Sen. John McCain issued a forceful statement condemning the face-to-face as "misguided" and "unnecessary."
"It plays right into Putin's hands by breaking his international isolation, undermining U.S. policy, and legitimizing Putin's destabilizing behavior — from dismembering Ukraine to propping Bashar Assad in Syria," McCain said Monday.
Beyond bridging the divides over Syria, Obama and Putin also were poised to discuss the problem of Ukraine — one of the main drivers of the broadening wedge between the U.S. and Russia.
After Russia's annexation of Crimea from Ukraine in March 2014, the U.S. and other Western nations imposed sanctions on Moscow. The U.S. also has accused Russia of supporting an insurgency in eastern Ukraine —allegations Moscow staunchly denies.
“The situation in Ukraine continues to be of significant concern and our support for the territorial integrity and sovereignty of Ukraine will be front and center throughout our discussions, particularly with President Putin,” Ben Rhodes, White House national security adviser, told reporters on Thursday.
However, the ongoing conflict in Syria — and Moscow's unmitigated support for embattled Assad — appears to have eclipsed the urgency of the Ukraine conflict heading into the annual General Assembly.