Mr Trump also says he "hadn't thought" about asking Mr Putin to extradite the dozen Russian military intelligence officers indicted this past week in Washington on charges related to the hacking of Democratic targets in the 2016 USA presidential election, but says "certainly I'll be asking about it".
In the CBS News interview, Trump declined to discuss his goals for the summit - "I'll let you know after the meeting", he said - but said he believes such sessions are beneficial.
After Trump labeled the EU a "foe", Donald Tusk, president of the European Council, responded on Twitter, using one of Trump's favorite stock phrases.
But Trump's chief diplomat, Secretary of State Mike Pompeo, told journalists travelling with him that he was confident the meeting would "put America in a better place". Bolton in an interview to ABC News said that it was unlikely that the U.S. would be able to arrest or extradite the 12 Russians who were indicted by a federal grand jury on Friday.
But many in Washington are leery of the summit occurring anywhere, believing that just by agreeing to meet, Trump has offered further global legitimacy to Putin, who will preside over the World Cup final in Moscow the day before the summit. Russia's a foe in certain respects. "China is a foe economically, certainly they are a foe", said Mr Trump. "They had bad defenses and they were able to be hacked". It doesn't mean anything. "It means that they are competitive", said Trump. "I go in with very low expectations". But if you look at the US media they mostly focus on potential risks.
Adding to the pressure on Trump is a new Justice Department indictment issued Friday accusing 12 Russian military intelligence officials of extensive hacking in 2016 that was specifically aimed at discrediting Clinton.
We won't back Chequers plan, says SNP
Others have voiced their support for May's premiership and against a future Labour prime minister. His replacement will be announced shortly.
Russian Federation would also take into consideration the effect of any possible "rapprochement" with the United States would have on its "allies and friends", Kortunov said, naming Iran, Syria, North Korea, Venezuela and China as examples of such countries.
Trump left for the summit after relaxing at one of his golf courses in Scotland following a tumultuous trip to Britain, which itself came after he bashed heads at a North Atlantic Treaty Organisation summit in Brussels.
Trump was later persuaded to do it overseas, tacking the summit onto his planned visit to Belgium and Britain.
He blamed the Democratic National Committee for "allowing themselves to be hacked".
Around 100 supporters of Trump, some wearing "Make Britain Great Again" hats, expressed their admiration for the president opposite the US embassy in London.
Trump and his aides have been working through the weekend to soften expectations for tangible results from the meeting.
Special Counsel Robert Mueller is investigating United States intelligence findings that Russians conspired to sway the 2016 election in Mr Trump's favour. "I did it. You got me, '" Trump said Friday, referring to Putin.