US President Trump has said he has “low expectations” for his meeting with Russia’s Vladimir Putin in Finland on Monday.
But he told CBS News that “nothing bad” and “maybe some good” would come out of the encounter.
He also said he would raise the subject of 12 Russians indicted for alleged hacking during the 2016 US election – but “hadn’t thought” about asking for their extradition.
Russia denies the allegations.
There are no extradition arrangements between Russia and the US.
There have been calls in the US for Mr Trump to cancel his meeting with Mr Putin over the indictments, announced on Friday by US Deputy Attorney General Rod Rosenstein.
Sunday also saw a protest march against the summit in Helsinki, Finland’s capital. Demonstrators chanted “media must be free”, and carried a banner calling for human rights.
Russia has said it is looking forward to the talks as a vehicle for improving relations.
But in an interview for ABC’s This Week programme, US National Security Adviser John Bolton said he found it “hard to believe” that Mr Putin did not know about the alleged hacking.
“That’s what one of the purposes of this meeting is, so the president can see eye to eye with President Putin and ask him about it,” he said.
“He’ll listen to President Putin’s response, and we’ll go from there.”
Mr Bolton said he was “quite concerned” that Russia would again try to undermine a US election and that there were a “lot of things going on” which he was unable to talk about because they were classified.
What did Trump tell CBS?
He said he “believed in meetings” and said his meetings with the North Korean and Chinese leaders had been a “very good thing”.
“I think it’s a good thing to meet. I do believe in meetings. I believe that having a meeting with Chairman Kim was a good thing. I think having meetings with the president of China was a very good thing. I believe it’s really good. So having meetings with Russia, China, North Korea, I believe in it. Nothing bad is going to come out of it, and maybe some good will come out,” he said.
“I can’t tell you what’s going to happen, but I can tell you what I’ll be asking for. And we’ll see if something comes of it,” he added.
Mr Trump also repeated his earlier criticism of the Obama administration, which was in power when the alleged hacking of Democratic party officials took place.
“This was during the Obama administration. They were doing whatever it was during the Obama administration,” he said.
“The DNC should be ashamed of themselves for allowing themselves to be hacked. They had bad defences and they were able to be hacked,” he added.
He said he had been told “by a number of people” that hackers had also targeted the Republican party but “we had much better defences”, although he added that “this may be wrong”.
What has Mr Trump been doing?
The US president has taken in a Nato summit and a visit to the UK ahead of his meeting with Mr Putin.
The visit has been controversial because of a newspaper interview in which he said the US would probably not give the UK a trade deal under the terms of Prime Minister May’s Brexit plans, and also said Europe was “losing its character” because of immigration from Africa and the Middle East.
He has since downplayed his Brexit comments – but speaking to the BBC on Sunday Mrs May said Mr Trump had advised her to “sue the EU”.
He is expected to leave the UK later after staying at his Turnberry resort on Scotland’s Ayrshire coast during the private leg of his visit.
What are the US hacking allegations?
The 11-count indictment names the Russians defendants, alleging they began cyber-attacks in March 2016 on the email accounts of staff for Hillary Clinton’s presidential campaign.
They are accused of using keystroke reading software to spy on the chair of the Democratic National Committee (DNC) and hack into the party’s computers.
Top Democrats including party chairman Tom Perez have urged Mr Trump to abandon the talks, saying Mr Putin was “not a friend of the United States”.
On the Republican side, Senator John McCain said the summit “should not move forward” unless the president “is prepared to hold Putin accountable”.
What’s the big picture?
Special Counsel Robert Mueller is investigating US intelligence findings that Russians conspired to sway the 2016 election in Mr Trump’s favour.
As of Friday, the inquiry has indicted 32 people – mostly Russian nationals in absentia – as well as three companies and four former Trump advisers.
None of the charges allege Trump advisers colluded with Russia to interfere with the presidential campaign.
Former National Security Adviser Michael Flynn and George Papadopoulos, a former foreign policy adviser, have pleaded guilty to making false statements about their contacts with Russians.
Former Trump campaign chairman Paul Manafort and his deputy Rick Gates were charged with money laundering relating to their political consultancy work in Ukraine.