President Biden said he warned Vladimir Putin in their meeting in Geneva on Wednesday that Russia will face stiff consequences if it conducts cyberattacks on critical U.S. infrastructure or allows opposition leader Alexei Navalny to die.

What he's saying: "Where we have differences, I want President Putin to understand why I say what I say, and why I do what I do. And how we will respond to different actions that harm America's interests," Biden said at a press conference following the summit, which was shorter than expected.

• On Navalny, Biden said he told Putin the consequences if he died in prison would be "devastating for Russia."
• On cybersecurity, Biden said he presented Putin with what the U.S. considers the critical elements of its infrastructure and told him the U.S. would respond forcefully — with cyber means of its own — if they were targeted. "We'll find out whether we have a cybersecurity arrangement that begins to bring some order," he said.
• On nuclear security, Biden said a strategic dialogue would be launched and the U.S. would know within the next six months to a year whether it was a serious process likely to yield results.

Key quotes from Biden's press conference:

• "How could I be the president of the United States of America and not speak out against the violation of human rights?"
• "The bottom line is, I told President Putin that we need to have some basic rules of the road that we can all abide by."
• "My agenda is not against Russia or anybody else. It's for the American people."
• Biden said Putin "still is concerned that we in fact are looking to take him down," but "the last thing he wants now is a cold war."

As to why the summit was shorter than planned, Biden said he and Putin covered all of the key issues in their meeting — with only their foreign ministers present — and then recapped those discussions with the larger group to ensure there were no misunderstandings.

The other side: During his own press conference after the meeting, Putin described the summit as "constructive" and said he did not think "there was any kind of hostility” between the two leaders.

• "Many of our joint positions are divergent, but nevertheless I think both sides manifested a determination to try and understand each other and try and converge our positions," Putin told reporters.
• "The meeting, you know, was actually very sufficient, and it was substantive and specific, and it was aimed at achieving results."

The big picture: Biden said he relayed to Putin human rights concerns on Navalny and jailed former U.S. Marines Trevor Reed and Paul Whelan.

• He also gave the Russian president a list of 16 critical infrastructure entities that are off limits as targets for cyberattacks and vowed to use the U.S.' "significant" cyber capabilities to respond if they are targeted.
• The most concrete result of the meeting was an agreement between the U.S. and Russia to immediately return ambassadors to their posts in Moscow and Washington, which Putin announced during his conference.

Go deeper: Biden and Putin conclude second round of closed-door talks

Editor's note: This is a breaking news story. Please check back for updates.