US President Joe Biden has warned Russian leader Vladimir Putin about election meddling in their first call as counterparts, the White House says.
The conversation included a discussion about the ongoing opposition protests in Russia and an extension of the last remaining US-Russia nuclear arms pact.
Mr Putin congratulated the new US president on winning the election, according to a Russian statement.
Both parties said they agreed to maintain contact moving forward.
Former US President Donald Trump sometimes undercut his own administration's tough posture on Russia and was accused of being too deferential to Mr Putin.
But former President Barack Obama - under whom Mr Biden served as vice-president - was also criticised for failing to check the Kremlin as it annexed Crimea, invaded eastern Ukraine and muscled in on Syria.
What did the White House and Kremlin say about the call?
"President Biden made clear that the United States will act firmly in defence of its national interests in response to actions by Russia that harm us or our allies," a US statement said.
A White House readout of Tuesday afternoon's call said that the two presidents also discussed the massive SolarWinds cyber-attack, which has been blamed on Moscow, reports that the Kremlin placed bounties on US soldiers in Afghanistan, and the poisoning of Russian opposition activist Alexei Navalny.
The Kremlin readout of the call did not refer to any points of friction the White House said had been raised by Mr Biden, who has in the past referred to Mr Putin as "a KGB thug".
Russian officials said their president had "noted that the normalisation of relations between Russia and the United States would meet the interests of both countries and - taking into account their special responsibility for maintaining security and stability in the world - of the entire international community".
"On the whole, the conversation between the leaders of Russia and the United States was of a business-like and frank nature," the Kremlin statement added.
The two leaders appeared to seal an agreement to renew New Start, an Obama-era accord that limits the amounts of warheads, missiles and launchers in the US-Russian nuclear arsenals.
It was due to expire next month, and Mr Trump had refused to sign on.
Biden doesn't want a confrontation
Joe Biden had indicated he would be tougher on Vladimir Putin than Donald Trump, who refused to take on the Kremlin and frequently cast doubt on Russian interference in the 2016 elections.
On that matter Mr Biden made his sharpest break with Mr Trump, reportedly telling Mr Putin that he knew Russia had tried to meddle in both the 2016 and 2020 elections. He also warned the Russian president that the US was ready to defend itself against cyber-espionage, and any other attacks.
Despite Mr Trump's conciliatory approach, the Kremlin did not benefit from his presidency, because his administration heavily sanctioned Russians for issues ranging from Ukraine to attacks on dissidents. Joe Biden and his foreign policy team will take a robust position on human rights and Mr Putin's intentions in Europe.
But they are not looking for a confrontation.
Rather, they hope to manage relations and co-operate where possible. In that vein, the two presidents did agree to work at completing the extension of the new Start arms control treaty before it expires next month.
What else did Biden do today?
The call with the Kremlin comes as Mr Biden's nominee for secretary of state, Antony Blinken, was confirmed by the Senate by a vote of 78-22.
Mr Biden later appeared at the White House to sign four executive orders aimed at addressing what he called US systemic racism.
"This is the time to act and it's to act because it's what the core values of this nation call us to do. I believe the vast majority of Democrats, Republicans and Independents share these values and want us to act as well," said Mr Biden.
The president directed the Department of Justice not to renew contracts with private prison operators, though advocates noted the order does not cover privately run immigration detention centres.
Mr Biden also directed the Department of Housing and Urban Development to take steps to eradicate racism from housing policy.
According to the Washington Post, the department will reinstate a 2013 rule on "disparate impact" that aims to block the real estate sector from requiring tenants to undergo criminal background checks, or using artificial intelligence to forecast creditworthiness.
The new orders also recommit the US government to respect tribal sovereignty. This is not seen as a significant change from existing federal policy, but some Native American officials have said their objections to public land decisions were ignored under the Trump administration.
Mr Biden also signed a directive rejecting coronavirus-related discrimination against the Asian-American and Pacific Islander communities.Meanwhile, Vice-President Kamala Harris received her second coronavirus vaccine dose at a federal health agency in Washington DC, saying: "I want to urge everyone to take the vaccine when it's your turn."
Ms Harris was criticised during last year's election campaign after she expressed doubt about the safety of any vaccine that might be developed under Mr Trump. The Moderna drug she was inoculated with on Tuesday was approved by the former Republican president's health officials.