Russian President Vladimir Putin has become one of the last world leaders to congratulate US President-elect Joe Biden on his victory.
The Kremlin had said it would wait for official results from November’s vote before recognising the victory.
Mr Biden was confirmed as the winner on Monday by the electoral college.
Most world leaders congratulated Mr Biden within days of the 3 November poll, when it was clear he had defeated sitting President Donald Trump.
Mr Biden and Mr Putin had frosty relations when the former served as vice-president under Barack Obama.
Democrat Joe Biden won November’s contest with 306 electoral college votes to Republican Donald Trump’s 232.
Confirmation by the electoral college, which took place on Monday, was one of the steps required for Mr Biden to take office.
Last month, President Trump said he would leave office in January if Mr Biden were affirmed as the election winner by the electoral college, but he has continued to make unsubstantiated claims of election fraud.
What did Putin say in his message?
According to a Kremlin statement, Mr Putin wished Mr Biden every success and said he was “ready for collaboration and contacts with you”.
He “expressed confidence that Russia and the United States, which have a special responsibility for global security and stability, could, despite their differences, really help to solve the many problems and challenges facing the world”, the statement added.
But analysts say Mr Biden, who describes Mr Putin as an autocrat, is expected to take a tougher line on Russia than Mr Trump.
Russia has faced accusations of interference in the 2016 US election to help get Mr Trump elected.
In US-Russian relations, personal chemistry is so important. Mikhail Gorbachev and Ronald Reagan had it. Boris Yeltsin and Bill Clinton, too. Putin and Biden? Don’t hold your breath.
On a trip to Moscow in his capacity as vice-president, Mr Biden concluded that Mr Putin had no soul. More recently he’s labelled Russia the greatest threat to America. Doesn’t sound promising, does it?
It doesn’t help that Vladimir Putin waited so long to congratulate America’s new leader. The Kremlin claimed it was doing things by the book, simply waiting for the official result. But the delay smacks of sour grapes.
There’s little doubt the Russian authorities would have preferred Donald Trump to be re-elected. Not that US-Russian relations flourished under his administration but at least he avoided criticising Russia and its leader. Plus, the weakening of the Western alliance under President Trump was viewed positively by Russian officials.
Moscow is bracing itself for a tougher US approach to Russia and, possibly, additional sanctions. But whatever political, ideological or personal differences they may have, Presidents Biden and Putin will need to develop some kind of working relationship. There are issues of global importance – like arms control – where co-operation between Russia and America is vital.
While Mr Putin waited nearly an month and a half before congratulating Mr Biden, in 2016 he congratulated Mr Trump on his victory the day after the vote.
How did Biden greet confirmation of his win?
In a speech after the announcement, he said it was “time to turn the page”. US democracy had been “pushed, tested and threatened”, he said, but it had “proved to be resilient, true and strong”.
He condemned Donald Trump’s attempts to overturn the result, referring to the president’s efforts to question the outcome and his legal challenges which have been rejected by courts across the country.
“Respecting the will of the people is at the heart of our democracy, even when we find those results hard to accept,” Mr Biden said, speaking in Delaware.
“The flame of democracy was lit in this nation a long time ago,” he added. “And we know that nothing not even a pandemic or an abuse of power can extinguish that flame.”
He also warned that, with the coronavirus pandemic continuing to ravage the US, there would be difficult months ahead.
“There is urgent work in front of us,” he said. “Getting this pandemic under control and getting the nation vaccinated against this virus.”
He was speaking as the Covid death toll in the US – the country worst affected by the virus – rose above 300,000.
What happened at the electoral college?
Normally the electors do not get that much attention but this year, after uncertainty generated by a raft of challenges to results in Democrat-won states by the Trump campaign, the state-by-state vote was in the spotlight.
Solidly Democrat California, with its 55 electors, was one of the last states to vote on Monday and took Mr Biden across the 270-vote threshold required to win the presidency.
Heightened security had been put in place in some states, including Michigan and Georgia, ahead of voting, which took place in state capitals and Washington DC.
In Michigan – a key swing state which Mr Biden won – legislative offices in the state capital Lansing were closed due to “credible” threats of violence.
The vote at the capitol building went ahead peacefully although a group of Republicans tried to enter the building to hold their own vote and were turned away.
In his speech, Mr Biden described the harassment of officials following the election as “unconscionable” and said: “It’s my sincere hope we never again see anyone subjected to the kind of threats and abuse we saw in this election.”
He also noted that he had the same number of electoral college votes that Mr Trump said was a “landslide” when the Republican won in 2016. Mr Biden emphasised that he had also won the popular vote, something Mr Trump failed to clinch four years ago.
Republican Senator Lamar Alexander said: “The presidential election is over. States have certified the votes. Courts have resolved disputes. The electors have voted. I hope that President Trump will put the country first, take pride in his considerable accomplishments, and help President-elect Biden get off to a good start.”
Curtain lowered on Trump court challenges
The quadrennial meeting of the US electoral college is usually a formality along the way to a presidential inauguration – a vestigial political event that long ago lost its power and relevance.
Donald Trump’s scorched-earth strategy of contesting the results of the 2020 election, however, gave the proceedings new attention.
His legal team has had little success in challenging the results in multiple battleground states and the official recording of the electoral college ballots effectively lowered the curtain on these long-shot judicial manoeuvres.
That does not mean the Trump team is giving up, of course. They will continue with futile court challenges and, eventually, ask Congress to overturn the election results.
It is an alternative reality that Donald Trump’s supporters may find more comforting than the one where Joe Biden is president-elect.
Given that the House of Representatives is controlled by Democrats, the official electoral college tally has been duly certified by the states and federal law is on Mr Biden’s side, Mr Trump’s chances of success in the real world, however, sit squarely at zero.
What happens next?
The results of the voting process will be sent to Washington DC and formally counted in a joint session of Congress on 6 January presided over by Vice-President Mike Pence.
That will pave the way for Joe Biden to be sworn in as president on 20 January.
Most Republicans have stood behind Mr Trump in his efforts to overturn the result, but some have broken ranks in recent weeks.
One Michigan congressman, Paul Mitchell, announced he was leaving the party weeks before his retirement in protest over what he said was its failure to accept that the election process was over.