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

Ahead of the summit, ABC News Chief Global Affairs Correspondent Martha Raddatz said Biden needs to walk a fine line in an effort not to alienate Putin.

"He wants the relationship to be better — the U.S.-Russia relationship — to be better than it has been," Raddatz said on ABC News Live Prime Tuesday. "And they both agree that it's at one of the lowest points in history."

"So, President Biden will have to give his grievances to Putin, telling him what he wants to do — and yet, we even heard a bit of that today, a little flattery, a little, you know, he is a 'tough guy,' he is a 'bright guy,' President Putin, and he is a 'worthy adversary,'" Raddatz continued. "That is diplomacy 101."

In a separate interview with ABC News' Linsey Davis, Masha Gessen, a staff writer at the New Yorker and author of "Surviving Autocracy," agreed that "Russian-American relations are at an all time low."

"Biden is faced with an incredibly difficult challenge," Gessen added.

Watch the interview:

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

Biden met with Swiss President Guy Parmelin and Foreign Minister Ignzio Cassis Tuesday and, according to a White House readout, Biden thanked the country for hosting the U.S. -Russia summit and "expressed appreciation for Switzerland's unique historical role providing a neutral ground for diplomacy and negotiations."

Biden and the leaders also talked about the strong relationships between the U.S. and Switzerland on many fronts. They also discussed Switzerland's role as the U.S. protecting power in Iran for 40 years and their contributions to the global COVID response effort.

-ABC News' Molly Nagle

The high-stakes meeting between Biden and Putin comes on the heels of a summit with NATO leaders in Belgium's capital, another first for Biden as U.S. president.

As NATO allies wrapped up talks, Biden said Sunday that he has the full support of NATO partners to meet with the Russian president. 

"What I'll convey to President Putin is that I'm not looking for conflict with Russia but that we will respond if Russia continues its harmful activities," Biden said at a press conference in Brussels. "And we will not fail to defend the trans-Atlantic alliance or stand up for democratic values."

Biden said not a single NATO leader expressed reservations about him meeting with Putin but rather have "thanked" him for doing it.

"I had discussions with them about -- in the open -- about what they thought was important from their perspective and what they thought was not important," he said.