The Russian leader said he did not want to see things like the Black Lives Matter movement and unrest happen in his country and criticized the arrest of many of those who attacked the US Capitol on Jan 6 during a protest to contest the certification of the 2020 US presidential election results by the US Congress.

"What we saw was disorder, disruption, violations of the law, et cetera," Putin said of the protests that followed the May 25 murder of George Floyd by a Minneapolis police officer. "We feel sympathy for the United States of America, but we don't want that to happen on our territory and we'll do our utmost in order to not allow it to happen," Putin said.

Biden said afterward that any comparison between what happened on Jan 6 and the Black Lives Matter movement was "ridiculous".

"It's one thing for literally criminals to break through a cordon, go into the Capitol, kill a police officer and be held unaccountable, than it is for people objectively marching on the capitol and saying 'You are not allowing me to speak freely,'" he said.

Biden said at his own news conference that it was important to meet in person so there could be no mistake about or misrepresentations about what he wanted to communicate.

"I did what I came to do," he said.

He said he told Putin certain US critical infrastructure "should be off limits" to cyberattacks, which Moscow has denied.

"I pointed out to him, we have significant cyber capability," Biden said. "In fact, (if) they violate basic norms, we will respond. ... I think that the last thing he wants now is a Cold War."

In a joint statement released after their meeting, the two heads of state noted both sides have "demonstrated that, even in periods of tension, they are able to make progress on our shared goals of ensuring predictability in the strategic sphere, reducing the risk of armed conflicts and the threat of nuclear war".

Stanley Renshon, a political scientist at City University of New York, also said that the fact that the bilateral meetings were much shorter than earlier indicated and that there were separate news conferences, suggest that the exchanges didn't lead to any substantive or in depth discussions.

Renshon said the common ground established at the summit would be vague generalities like calling the discussions "constructive" by Putin or hoping for a relationship that is more "predictable" and "stable" by Biden.

"Atmospherics rarely overcome national interests and those of the leaders involved in this meeting is no exception," he said in an email.

The two sides agreeing for their ambassadors to resume their posts can be seen as a gesture of diplomatic healing.

Russia's Ambassador to the US Anatoly Antonov was recalled from Washington in March after Biden called Putin a "killer", and US envoy to Russia John Sullivan left Moscow in April.

"If this summit just leads to a mutual return of ambassadors, that will be quite an important step in positive diplomacy. The tone of both presidents also represented a return to standard diplomacy," noted Anatol Lieven, a professor at Georgetown University and a senior fellow of the Quincy Institute for Responsible Statecraft in Washington DC.