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

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.

Biden and Putin's meeting is slated to begin on Wednesday around 7 a.m. ET and last four to five hours total, with multiple sessions.  

The two leaders will first take part in a small session, joined by U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov, before taking part in a larger working session.

The two leaders are also expected to host dueling, solo press conferences following the summit.

Biden said they weren't holding a joint news conference, as Trump did with Putin, because he didn't want the focus to be on talking time or body language. Doing it this way leaves Putin with less of an opportunity to embarrass the American president, as he's historically tried to do.

"I think the best way to deal with this is for he and I to meet, he and I to have our discussion," Biden said Sunday in England, on another leg of his first trip as president. "I don't want to get into being diverted by, did they shake hands, who talked the most and the rest."

While he is no stranger to Putin, Biden has been intensely prepping for the meeting, receiving at least once-a-day briefings for weeks leading up to the summit.

"He's been preparing for this like he prepares for every significant international engagement. He reviews the issues -- written material; he cares about digging into the details. That very much matters to him," a senior administration official said Tuesday.

The White House has also called on experts to help Biden prep for the meeting -- including Fiona Hill, a top Russia expert and National Security and former Trump administration official who famously said she considered faking a medical emergency to end Trump’s press conference with Putin in 2018 in Helsinki, Finland. 

Wednesday's meeting is slated to last four to five hours total, with multiple sessions.

-ABC News' Molly Nagle