media captionBiden and Putin have first conversation ahead of summit
The presidents of the US and Russia have praised their talks in Geneva but have made little concrete progress at the first such meeting since 2018.
Disagreements were stated, said US President Joe Biden, but not in a hyperbolic way, and he said Russia did not want a new Cold War.
Russian President Vladimir Putin said Mr Biden was an experienced statesman and the two "spoke the same language".
The talks lasted four hours, less time than was scheduled.
Mr Biden said they did not need to spend more time talking and there was now a genuine prospect to improve relations with Russia.
The two sides agreed to begin a dialogue on nuclear arms control. They also said they would return ambassadors to each other's capitals – the envoys were mutually withdrawn for consultations in March, after the US accused Russia of meddling in the 2020 presidential election.
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However, there was little sign of agreement on other issues, including cyber-security, Ukraine and the fate of Russian opposition leader Alexei Navalny, who is currently serving a two-and-a-half-year sentence in a penal colony.
What did the leaders discuss?
Before the summit, both sides said relations were at rock bottom.
Mr Putin hinted at a possible deal on exchanging prisoners, saying he believed compromises could be found.
On cyber-attacks, Mr Putin brushed away accusations of Russian responsibility, saying that most cyber-attacks in Russia originated from the US.
Mr Biden said he told Mr Putin that critical infrastructure, such as water or energy, must be "off-limits" to hacking or other attacks.
The two sides differed sharply on human rights, including the right to protest.
Mr Putin dismissed US concerns about Alexei Navalny, who recently undertook a 24-day hunger strike.
He said Navalny ignored the law and knew that he would face imprisonment when he returned to Russia after having sought medical treatment in Germany. Navalny says he was poisoned with a nerve agent on Mr Putin's orders – an accusation Mr Putin denies.
He said Russia did not want disturbances on its territory comparable to the Capitol riots or the Black Lives Matter movement.
Mr Biden dismissed Mr Putin's comments about Black Lives Matter as "ridiculous", and said human rights would "always be on the table".
BBC Moscow correspondent Sarah Rainsford says Mr Putin was keen to underline several times that Russia was a nuclear power – an important country, with an economy smaller than that of the US, but one that still mattered and that was why Mr Biden had come to talk to him.