Biden-Putin summit highlights: 'I did what I came to do,' Biden said

White House officials have significantly downplayed the prospect of a prisoner swap for two U.S. Marine veterans, Trevor Reed and Paul Whelan, being held in Russia, ahead of the meetings.

"That's certainly something the Russians have been pushing for," said ABC News Chief White House Correspondent Cecilia Vega. "They have basically said this could encourage the Kremlin to target more Americans unfairly like they believe these two Americans there were targeted."

Russian officials have indicated they would like to trade Reed and Whelan for two Russians held in the U.S.: Viktor Bout -- one of the world's most notorious arms dealers and dubbed "the Merchant of Death" — and also Konstantin Yaroshenko, a pilot currently serving a lengthy jail sentence for a drug smuggling conviction.

Whelan's family overnight released an audio message from him recorded from the prison camp in central Russia where he is held. In it, he appealed to Biden to help free him.

A White House official confirmed the expanded bilateral meeting started about an hour ago, at 4 p.m. local time (10 a.m. ET).

ABC News Correspondent Karen Travers said the summit is about setting the U.S.-Russia relationship on a new path forward to a more stable, predictable relationship.

"In terms of the stakes, it's been striking to hear officials on both sides say over the last few days heading into this summit that there are very low expectations for some major breakthrough between President Biden and President Putin," Travers said. "This is all about starting a conversation."

She also noted how different this meeting looks from President Donald Trump's encounter Putin in Helsinki in 2018, and the two took questions standing side-by-side at a joint news conference.

ABC News Chief Global Affairs Correspondent Martha Raddatz highlighted the "incredible" body language seen in Biden and Putin's face-to-face meeting and said the images captured there already make the summit a success for Putin.

"I think President Putin, you saw those pictures of president Putin with President Biden. That's essentially what he wants right there," Raddatz said. "The relaxed President Putin sitting back in his chair, Joe Biden looking relaxed as well. All of this is so rehearsed."

"They know the world is looking at those pictures, especially Vladimir Putin. He wants to be on the world stage," she added.

Even with Putin denying Russian involvement in recent U.S. cyberattacks, his refusal to discuss imprisoned opposition leader Alexey Navalny with Biden going into the meeting, and the two leaders still likely to air their grievances in dueling press conferences later, Raddatz said, since relations are so low, any progress will be a win.

"I think because they have lowered the bar so far, but it's still a bar, that any progress will be seen as a win according to Joe Biden and probably according to Vladimir Putin, too," she said.

The first meeting between Biden, Putin, U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov has concluded after about an hour and a half, according to a White House and Russian officials.

"They are moving into the expanded bilateral meeting," a White House official said, with five aides present on each side, including the U.S. and Russian ambassadors.

On the U.S. side, Blinken, national security adviser Jake Sullivan, Undersecretary of State for Political Affairs Victoria Nuland, U.S. Ambassador to Russia John Sullivan and National Security Council Russia experts Eric Green and Stergos Kaloudis, are accompanying Biden.

The Russian delegation is expected to include Lavrov, Putin’s foreign affairs adviser Yuri Ushakov, Lavrov’s deputy Sergei Ryabkov, the chief of the General Staff of the Russian military Gen. Valery Gerasimov, Russian ambassador to Washington Anatoly Antonov. Kremlin envoys on Ukraine and Syria, as well as Putin’s spokesman, Dmitry Peskov, are also expected to attend.

-ABC News' Ben Gittleson