Putin publicly denied the "so-called interference" allegations and admitted that he had wanted Trump to win the election.
The extraordinary news conference in Finland came four days after the Justice Department released an exceptionally detailed indictment of 12 Russian military intelligence officers, showing how they interfered in the campaign with precision by hacking the DNC and strategically releasing the Democrats' e-mails.
Trump has been reluctant to blame Russian Federation for the hacks and again Monday refused to embrace the intelligence community assessment.
POTUS said he was "fascinated" by Putin's suggestion Robert Mueller's team go work with his people to make the case about those 12 Russian military officials indicted in Friday for tampering with the U.S.'s 2016 election.
Mr Putin described the Helsinki meeting as "candid and useful" while Mr Trump said there had been "deeply productive dialogue". "I don't want to insult President Trump when I say this - and I may come [across] as rude - but before he announced that he will run for [the] presidency, he was of no interest for us".
"I think the probe is a disaster for our country", Trump said.
Putin claimed Russian Federation did not interfere in the U.S. presidential election, contradicting conclusions made by USA intelligence agencies. Both heads of state will also have a bilateral meeting with Niinistö.
Some career diplomats also expressed alarm.
Earlier Monday, House Minority Leader Nancy Pelosi (D-Calif.) said that Trump's performance in Helsinki "proves that the Russians have something on the president, personally, financially, or politically".
Hours after the Helsinki summit, Trump tweeted: "I have GREAT confidence in MY intelligence people".
Brennan, among other critics, felt this was inappropriate and slammed Trump for doing so.
Mr Trump confirmed that he addressed meddling by Russia in the 2016 USA election with his Russian opposite number, but the U.S. leader is not condemning Moscow's conduct publicly.
COSTER: What do you expect to be the reaction among USA allies - in public and in private?
Liina Isto deputy chair of Finns Party Youth Wing. Image Yle Zena Iovino
"They said they think it's Russia; I have President Putin, he just said it's not Russia", Trump told reporters with Putin by his side. "This answer by President Trump will be seen by Russian Federation as a sign of weakness and create far more problems than it solves".
The White House said Trump would meet with members of Congress on Tuesday. It gave no further details.
The day of the Trump-Putin summit began slowly.
"The president must appreciate that Russian Federation is not our ally", Ryan said, in what was, for the mild-mannered speaker, akin to a reprimand.
The Russian foreign ministry responded, first by liking Mr Trump's tweet and then replying: "We agree". "He and Putin seemed to be speaking from the same script as the president made a conscious choice to defend a tyrant against the fair questions of a free press, and to grant Putin an uncontested platform to spew propaganda and lies to the world".
A lot of the questions focused on Russia's intrusion into the United States election campaign (the considered position of the key U.S. intelligence agencies) and specifically the indictment by the Mueller probe of 12 Russian intelligence agents.
"I beat Hillary Clinton easily and frankly we beat her..."
Trump's warm words for Russian Federation were a marked contrast from the past week, when he repeatedly rebuked long-standing US allies at a North Atlantic Treaty Organisation summit and during a visit to Britain. He said it as strong as you can say it.
Chait suggests that Trump may have been compromised by the KGB, to which Putin once belonged.
U.S. Sen. Jim Risch's comments joined a flood of reactions to Monday's two-hour, one-on-one meeting between Putin and President Donald Trump in Helsinki, Finland.
With attempts to reset relations with Russian Federation by former presidents George W. Bush and Barack Obama, Browder said appeasement simply doesn't work with a criminal like Putin. He referred to the European Union as a "foe" in trade and repeatedly criticized it.
"If there is meddling in the election this November like we saw in 2016, we're not going to have much of a relationship left", Huntsman Jr. told Fox News Sunday. "The first clear outcome can only be that we need to align ourselves even more closely in Europe".
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