Russian leader Vladimir Putin and US President Joe Biden are to meet in Geneva on June 16 amid the biggest crisis in ties between their two countries in recent history.
Here are five key issues the leaders are expected to discuss:
Election meddling, cyberattacks
The United States has for years accused Russia of meddling in elections and launching cyberattacks against government agencies and private companies.
Biden's administration in April sanctioned Russia over the SolarWinds cyberattack that hit federal organisations and more than 100 US companies, and for alleged meddling in the 2020 presidential election.
More recently, the White House linked Russia to a cyberattack against the global meat processing giant JBS.
Russia rejects the claims and in turn, has accused Washington of backing its political opposition and funding organisations and media critical of the Kremlin.
Navalny, human rights
Biden has said he plans to underscore Washington's commitment "to stand up for human rights and dignity" at the summit.
Russia's opposition says authorities have stepped up a crackdown since January when Kremlin critic Alexei Navalny returned from Germany where he underwent treatment for a near-fatal poisoning attack.
Navalny was imprisoned in February, and authorities are moving to outlaw his political movement.
Putin has accused Washington of "double standards" and seeking to interfere in Russian domestic affairs. In turn, he defended protesters who stormed the Capitol, saying they had legitimate political demands.
Russia's Foreign Minister Sergei Lavrov has recently accused Hollywood of censorship and said the United States had taken political correctness to the point of "absurdity".
Arms control, conflicts
Moscow and Washington have in recent years accused each other of breaching security agreements, and one key arms accord, the Intermediate-Range Nuclear Forces Treaty, was scrapped after Donald Trump pulled out in 2019.
Putin in June formally removed Russia from the Open Skies agreement that allowed signatories to fly surveillance flights and share results with allies after the US exited last year.
But Putin and Biden extended in February the New START nuclear treaty — the last remaining arms reduction pact between Russia and the United States.
Putin has warned of a new arms race and made much of Russia's next generation weapons that he says render Western missile defence systems obsolete.
Tensions persist over conflicts in Syria, Libya and Ukraine. In April, Russia amassed more than 100,000 troops near the Ukrainian border and in Crimea, prompting warnings from NATO.
Diplomatic tensions
Diplomatic tensions between Moscow and Washington have skyrocketed since Biden took office.
After Biden in March likened Putin to a "killer," Russia in a rare step recalled its ambassador for consultations and said the US envoy likewise should return to Washington.
When the United States announced the hacking sanctions against Russia in April it also expelled 10 Russian diplomats. Moscow retaliated in kind and barred the US embassy from employing foreign nationals.
The US mission was forced to suspend most consular services.
In May, Russia formally designated the United States an "unfriendly" state. The only other country on that list is the Czech Republic.
Prisoners
The fate of a number of prisoners is expected to be on the agenda as well.
Former US marine Paul Whelan was jailed for 16 years by Russia for espionage. He has urged Biden to arrange a prisoner exchange and said in a recent interview he was victim of hostage diplomacy.
Another US citizen, Trevor Reed, was sentenced to nine years in prison in 2020 on charges of assaulting Russian police officers while drunk.
Moscow could be eyeing the return of the notorious Russian arms dealer imprisoned by the United States, Viktor Bout, and a contract pilot and alleged drug trafficker, Konstantin Yaroshenko.
Bout's elderly mother has appealed to both Biden and Putin to negotiate her son's release.
