WASHINGTON - The Obama administration suggested Thursday that Russian President Vladimir Putin personally authorized the hacking of Democratic officials' email accounts in the run-up to the presidential election and said it was "fact" that such actions helped Donald Trump's campaign. The White House also assailed Trump himself, saying he must have known of Russia's interference.

No proof was offered for any of the accusations, the latest to unsettle America's uneasy transition from eight years under Democratic President Obama to a new Republican administration led by Trump. The claims of Russian meddling in the election also have heightened already debilitating tensions between Washington and Moscow over Syria, Ukraine, and a host of other disagreements.

"Only Russia's senior-most officials could have authorized these activities," White House spokesman Josh Earnest said, repeating the words from an October U.S. intelligence assessment.

Obama's deputy national security adviser, Ben Rhodes, connected the dots further, saying it was Putin who was responsible for the Russian actions.

"I don't think things happen in the Russian government of this consequence without Vladimir Putin knowing about it," Rhodes said on MSNBC.

The accusation paints Putin, the leader of perhaps the nation's greatest geopolitical foe, as having directly undermined U.S. democracy. U.S. officials have not contended, however, that Trump would have been defeated by Hillary Clinton on Nov. 8 if not for Russia's assistance. Nor has there has been any indication of tampering with the vote-counting.

The Kremlin flatly rejected the claim of Putin's involvement, with Putin spokesman Dmitry Peskov dismissing it Thursday as "laughable nonsense."

The Russia dispute is fueling an increasingly public spat between Obama's White House and Trump's team that is threatening to spoil the delicate truce that Obama and Trump have forged since Election Day.

Although the president and president-elect have avoided criticizing each other publicly since Trump's win, their aides have been more openly antagonistic. Kellyanne Conway, Trump's senior transition adviser, said it was "breathtaking" and irresponsible that the White House had suggested Trump knew Russia was interfering to help his campaign.

That led Obama spokesman Josh Earnest on Thursday to unload, arguing that Trump, who has dismissed the CIA's assessment of Russian interference, should spend less time attacking the intelligence community and more time supporting the investigation that Obama has ordered.

Earnest said it was "obvious" Trump knew what Russia was doing during the campaign, pointing out that Trump had encouraged Moscow during a news conference to find Clinton's missing emails. Trump has said he was joking.

"I don't think anybody at the White House thinks it's funny that an adversary of the United States engaged in malicious cyber activity to destabilize our democracy," Earnest said. "That's not a joke."

U.S. intelligence officials have linked the hacking to Russia's intelligence agency and its military intelligence division. Moscow has denied all accusations that it orchestrated the hacking of email accounts of Democratic Party officials and Clinton's campaign chief, John Podesta, and then leaked them to the antisecrecy website WikiLeaks.

Obama said Thursday that anytime a foreign government tries to interfere in U.S. elections, the nation must take action - "and we will."

"Some of it may be explicit and publicized, some of it may not be," Obama told NPR News. "But Mr. Putin is well aware of my feelings about this, because I spoke to him directly about it."

Trump and his supporters insist the Democrats' outrage about Russia is really an attempt to undermine the validity of his election victory. Rep. Peter King, a Trump ally and New York Republican, called it "disgraceful."

"Right now, certain elements of the media, certain elements of the intelligence community and certain politicians are really doing the work of the Russians," King said.

Still, Democrats pounced on the latest suggestions of Putin being connected to the daily drip of emails during the presidential race from some of Clinton's closest advisers. Putin was "clearly involved," said outgoing Senate Minority Leader Harry Reid.

"Having been the former head of the KGB, does that surprise you?" Reid said. "And does it surprise anybody today when he denied it?"