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

In a photo-op surrounded by chaos, some reporters were let inside a small door leading to the room where Biden and Putin were already sitting down for the first meeting of their summit.

"I would like to thank you for your initiative in today's meeting," Putin said, according to a transcript from the Kremlin. "I know you've had a long trip, a lot of work. Nevertheless, there are many issues in Russian-American relations that need to be discussed at the highest level, and I hope that our meeting will be productive."

Biden replied, "Thank you, as I said outside, I think it's always better to meet face-to-face. I’m trying to determine where we have mutual interests and we can cooperate. And where we don't, establish a predictable and rational way in which we disagree. Two great powers."

The summit is expected to go as long as five hours, and while the two leaders are expected to take breaks and expand their meeting to a larger group, no updates are expected until their dueling solo press conferences later.

At least two American reporters who made it inside the meeting said afterward that Russian security pulled on their clothes as they tried to push the journalists out.

When Russian security yelled and shoved at journalists to get out, both press and White House officials "screamed back that the Russian security should stop touching us," according to a pool reporter.

"Both presidents watched and listened to the media scuffle in front of them. They appeared amused by the scene," the reporter said.

The media scrum also appeared to momentarily delay the Swiss president’s departure from the villa. His motorcade pulled up for him to leave, and officials or security tried to move the reporters out of the way. The Swiss president came out and was able to pull away.

One critical message the president will carry, according to U.S. Secretary of State Antony Blinken, is demanding that Russia stop "harboring in any way criminal organizations engaged in cyberattacks, including ransomware" and urging "Russian cooperation in dealing with these criminal organizations to the extent they're operating from Russian territory."

But tough talk and mounting U.S. sanctions have not deterred Russian behavior, from crackdowns against domestic political opposition and pro-democracy movements to aggression overseas against neighbors Ukraine and Georgia or western democracies and their elections.

Pressed on that Sunday by ABC "This Week" co-anchor Martha Raddatz, Blinken said U.S. sanctions "can be" effective, "especially when they're done in coordination with other countries."

To that end, he emphasized what the administration had said was the importance of Biden meeting American allies in the Group of Seven, NATO and the European Union before sitting down with Putin.

But some of those alliances are bruised after four years of former President Donald Trump's badgering and questioning -- with many Europeans in particular unsure whether "Trumpism" is here to stay or whether "America is back," as Biden has made his tagline for this trip.

Blinken didn't take that political question head on, but he said the U.S. and its allied democracies have "to actually demonstrate in concrete ways that democracies working together are making a difference for their people and for people around the world" -- especially in contrast to Russia and China.

-ABC News' Conor Finnegan

Putin's plane landed in Geneva on Wednesday at around 12:30 p.m. local time (6:30 a.m. ET), as planned, ahead of his meeting with Biden.

The Russian president was seen descending a covered staircase from his jet to the tarmac, where several black cars comprising his motorcade awaited. He gave a small wave before getting in one of the cars. His motorcade departed the tarmac at 12:41 p.m. local time (6:41 a.m. ET).

Biden arrived in Geneva on Tuesday.

Swiss President Guy Parmelin is scheduled to greet Biden and Putin at Villa La Grange, where their much-awaited summit is taking place, at 1:10 p.m. local time (7:10 a.m. ET). Parmelin is then expected to deliver welcome remarks and pose for a photo with Biden and Putin before the two leaders begin their meeting.

-ABC News' Molly Nagle and Jordyn Phelps.