On Hacking, Obama Told Putin, 'Cut It Out'

President Barack Obama says that after government officials realized Russia had hacked the Democratic National Committee email system, he told Russian President Vladimir Putin to "cut it out" during a G-20 meeting in China in September.

During his year-end news conference at the White House on Friday — possibly the last full news conference of his presidency — Obama said American intelligence officials became aware about six months ago of the extent to which Russian hackers had penetrated the DNC. The president said his main concern was to ensure the cyberattacks did not escalate, compounding the problem, and "affect the actual election process itself."

To make sure that didn't happen, Obama said, when he saw Putin in China, "I felt that the most effective way ... was to talk to him directly and tell him to cut it out, and [that] there were going to be serious consequences if he didn't."

WATCH: Obama on Talking to Putin on Hacking US Election

Obama on Talking to Putin on Hacking US Election

"We did not see further tampering of the election process, but the leaks from WikiLeaks were already out there," he added.

When asked whether he thought the U.S. general election last month was a free and fair vote, Obama said: "I can assure the public that there was not the kind of tampering with the voting process that was a concern and will continue to be a concern; that the votes that were cast were counted, they were counted appropriately. We have not seen evidence of machines being tampered with. That assurance, I can provide."

Defends U.S. restraint

Critics have complained the Obama administration did not do enough to respond to the hacking, or to make clear Russia's direct involvement in the computer intrusions. Some contend that the government's arm's-length handling of the issue may have affected the outcome of the election, in which first-time candidate Donald Trump, running as a Republican, defeated the Democratic Party's candidate, former Secretary of State Hillary Clinton, in what was seen as a huge upset.

"We handled it the way it should have been handled," Obama told reporters, by allowing law enforcement agencies "to do their jobs," monitoring the progress of the election.

WATCH: Obama on How US Will Respond to Russian Hacking

Obama on How US Will Respond to Russian Hacking

If he, as president, had commented more on the hacking, Obama said, the issue "would have become a political scrum."

The U.S. was caught up in a "hyperpartisan atmosphere" during the late stages of the election campaign, the president said, and his main concern was the integrity of the election process. He said he wanted to make sure Americans understood the White House was trying to "play this thing straight," favoring neither side in the Trump-Clinton contest.

What about the media?

Obama also took members of the news media to task for their role in election coverage.

"I'm finding it a little curious that everybody's acting surprised that this [news about the Russian hacking effort] would have undermined the election of Hillary Clinton," he said, gazing at his audience of reporters in the White House briefing room, "because you guys wrote about it every day. ... This was an obsession that dominated the news coverage."

The computer intrusion was not some elaborate, complicated espionage scheme, Obama said. "They hacked into some Democratic Party emails that contained fairly routine stuff. Some of it [was] embarrassing or controversial. ... And then it just took off. But the truth of the matter is that everybody had the information."

Hacking emails, then leaking their contents to the public piecemeal, day by day, raised several issues, the president said, including the growing challenges of cybersecurity.

More cybersecurity needed

"We are a digital culture," Obama said. "There is not a branch of our government that somebody is not phishing for something ... and this is why for the last eight years [he has struggled] with how to do we continually upgrade our cybersecurity system."

The president also was asked several times to discuss the situation in Syria, including what he could have done differently to limit the enormous bloodshed in that lengthy civil war.

WATCH: Obama on US Involvement in Syria

Obama on US Involvement in Syria

Obama conceded the war in Syria was "one of the hardest issues I've faced." The world, he said, "is united in horror at the savage assault by the Syrian regime and its Russian and Iranian allies on the city of Aleppo."

"This blood and these atrocities are on their hands," Obama said, making clear he was referring to leaders in Moscow, Damascus and Tehran. He was speaking just hours after the Syrian government suspended the evacuation of civilians and fighters from the last rebel-held portions of Aleppo city, leaving the fate of tens of thousands of people highly uncertain.

Obama has been criticized for failing to take more direct action, including the use of greater numbers of U.S. troops, to end the conflict in Syria. He admitted he could understand the intense desire for more action by the U.S., but said that it would have been impossible to accomplish anything "on the cheap," without a full U.S. military intervention.

President Barack Obama speaks during a news conference, Dec. 16, 2016, in the briefing room of the White House in Washington.

Syria action required unity

Left unsaid was the certain reluctance of the administration's Republican foes, who control Congress, to sign on to expensive and expansive intervention in Syria.

"Unless we were all in and willing to take over Syria, we were going to have problems," Obama said. Any further U.S. involvement, he added, would have required "putting large numbers of U.S. troops on the ground, uninvited, without any international law mandate."

Asked about his contacts with Trump, Obama said their conversations had been cordial and had included specific suggestions, and he pledged he would continue to make himself available for consultations or other assistance to Trump, just as previous presidents made themselves available to him.

To a questioner who appeared to be inviting Obama to criticize Trump's abrupt and controversial comments about events of international and national importance, including blunt comments on Twitter, the president declined to disparage his successor. Trump, he said, "is still in transition mode" — meaning he is still adapting from his former life as a business executive and a sharp-tongued television star to his next four-year assignment, as commander in chief and chief executive of the United States.

"As I've said before, I think that the president-elect is still in transition mode, from campaign to governance. ... He still has campaign spokesmen sort of filling in [for him] and appearing on cable shows. There's just a whole different attitude and vibe when you're not in power, as when you are in power," the president added.

'All should agree on Russia's role'

Asked about Trump's dismissal and denial of reports of Russian government involvement in the U.S. political campaign hacking, Obama said, "The Russians were responsible for hacking the DNC. ... That should be a bipartisan issue — that shouldn't be a partisan issue.

"My hope is that the president-elect is going to be similarly concerned that we shouldn't have foreign interference in our election process," Obama said. "The transition from election season to governance season is not always smooth. You know it's bumpy. When Donald Trump takes the oath of office and is sworn in, he's got a different set of responsibilities and considerations."

At one point, Obama raised a statistic from a poll that said one-third of Republican voters had a favorable opinion of Russia's Putin, a former KGB agent who has been accused by his foes of corruption, harassment, illegal imprisonment of enemies and the ordering of assassinations.

"Ronald Reagan would roll over in his grave," Obama said, if he were to learn that more members of his Republican Party approved of the Kremlin leader than of the sitting president of the United States. "And how did that happen? ... Because for too long, everything that happens in this town, everything that's said, is through the prism of, 'Does this help or hurt us relative to Democrats? Relative to President Obama?'

"We've lost track of what we're about and what we stand for," Obama said.

Eight years of accomplishments

Obama began the year-end news conference by reviewing not only his administration's successes and failures during 2016, but also such efforts throughout his presidency, which began on January 20, 2009.

Highlights of his two terms as president, Obama said, included sharply reducing unemployment, providing health care coverage to millions of previously uninsured Americans, restoring U.S. relations with Cuba, and getting nearly 200 nations to sign on to a world agreement to limit the effects of climate change and to slow global warming.

"By so many measures, our country is better now than when we started," Obama said.

Shortly after the afternoon meeting in Washington with reporters, Obama and his family left for Hawaii, where they will spend the Christmas and New Year holidays.