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.

"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

Biden arrived in Geneva earlier Tuesday less than 24 hours ahead of his meeting with Putin, scheduled for Wednesday around 7 a.m. ET and expected to last several hours.

Looking to project confidence ahead of the high-stakes summit, Biden didn’t miss a beat during a photo op Tuesday with Swiss President Guy Parmelin.

"Mr. President, are you ready for tomorrow?" a reporter asked.

"I’m always ready," Biden replied.

The meeting with the Swiss president was Biden's final public event for the day.

When the president arrived earlier in Geneva, he was met with a long line of greeters, many dressed in colorful outfits, as he stepped off Air Force One.

The White House said Biden will hold a solo press conference after meeting with Putin, where he will give his takeaways. Putin plans to do the same.

When Putin meets Biden on Wednesday in Switzerland, experts in Moscow say for all their differences, the two leaders want something similar from their first summit: to cool things down.

The U.S. and Russia's relations are the worst they have been since the Cold War and since 2016 in particular seem locked in almost permanent crises.

Biden has said he wants a more stable and predictable relationship with Russia, one that would allow it to focus on other foreign policy priorities that are more important to it, like taking a harder line with China. The Kremlin for its part has faced a continuous and intensifying barrage of sanctions-- the latest in April-- and with its crackdown on opposition at home and aggressive actions abroad is increasingly becoming a pariah with western countries.

Since coming to office, Russia has appeared to want to get Biden's attention. The president offered Putin the summit after Russia massed thousands of troops on Ukraine's border in April.

But now, having got Biden to the table, analysts said Putin has a clear proposal to deliver in Geneva: stay out of Russian domestic politics and Russia might act less troublesome abroad.

"The Kremlin wants to transition to a respectful adversarial relationship from a disrespectful one we have today," said Vladimir Frolov, a former diplomat at Russia's embassy in Washington and now a commentator on foreign affairs.

"That is, it wants to be treated the same way the Soviet Politburo was treated by the US in 1970-80s," Frolov told ABC News. "Meaning no name-calling" — such as Biden calling Putin a "killer" — "no personal sanctions on the leadership, no democracy lectures, regular personal summit meetings; respectful tone of discussions, no tangible support for Russian opposition."

It will not be an invitation for détente but instead to return to the later years of the Cold War when Putin was a KGB agent and the Soviet Union and the U.S. saw each other as enemies but tried to maintain a predictable relationship. And, crucially, where Russia was treated as an equal.

"For this, the Kremlin is prepared to promise to behave more responsibly," Frolov said.

"This seems to be in line with what the White House sees as a desirable deliverable," he continued. "So unless one of the leaders stormed out of the meeting shouting expletives, the summit would be a major success."

-ABC News' Patrick Reevell