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

Amid all the high-level shadow boxing setting up President Joe Biden's summit with Russian President Vladimir Putin, Biden has added a new wrinkle -- one that amounts to a test for himself that awaits him back home.

Biden has cast this moment in the world community in broad terms for the United States -- a chance to assert the power of democratic nations in the face of challenges from China and Russia in particular. Asked Monday what he is telling allies who may be worried about any American slide toward autocracy, Biden again went big.

"What I'm saying to them is, watch me," Biden said. "That's why it's so important that I succeed in my agenda."

Biden was nonchalant in his condemnation of what he called the "phony populism" of former President Donald Trump. Speaking about Republicans, he flatly observed that "the Trump wing of the party is the bulk of the party, but it makes up a significant minority of the American people."

Still, just hours earlier, Senate Minority Leader Mitch McConnell served notice that his brand of hardball is still going to be played, with a warning about what Republican Senate control would mean for any Supreme Court vacancy under a Democratic presidency.

McConnell is objecting to congressional scrutiny of Trump-era Justice Department strategies, just like he did to the proposed Jan. 6 commission. And it's still far from clear whether any infrastructure or climate-change legislation can pass with Republican support, to say nothing of the prospects for tax reform.

Asked about Putin's laughing response to Biden's assertion that he is a killer, Biden said his message back would be that he is laughing as well. The world now is watching -- and will still be when Biden and Putin are both back home.

-ABC News Political Director Rick Klein