President Trump's chief diplomat, Secretary of State Mike Pompeo, said Mr. Trump and Putin should meet as planned on Monday in Helsinki, Finland.

"I am confident that President Trump's meeting with Vladimir Putin will put America in a better place. It's very important that they meet," Pompeo told journalists traveling with him.

Pompeo's comments come as some Democrats call on the president to cancel his meeting with Putin or decline to meet with him one-on-one unless he stands up to the foreign leader, particularly after Deputy Attorney General Rod Rosenstein announced the indictment of 12 Russian intelligence officers accused of election meddling.

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Mr. Trump says he will bring up election meddling with Putin, but according to Russian Foreign Minister Sergey Lavrov, only Putin, Mr. Trump and interpreters will be in the room -- and that, he claimed to the Russian outlet RT, is what the U.S. requested. The meeting will be followed by a joint presser, a White House official told the press pool.

Mr. Trump spent part of Saturday playing golf and tweeting about his predecessor and CNN, which he accuses of covering him unfairly. Aides had said Mr. Trump would spend the weekend preparing for Monday's meeting with Putin.

I have arrived in Scotland and will be at Trump Turnberry for two days of meetings, calls and hopefully, some golf - my primary form of exercise! The weather is beautiful, and this place is incredible! Tomorrow I go to Helsinki for a Monday meeting with Vladimir Putin. — Donald J. Trump (@realDonaldTrump) July 14, 2018

Mr. Trump was later seen on the links. A BBC reporter recorded footage of him waving at protesters as they shouted "No Trump, No KKK, No Racist USA!" before resuming his game.

President Trump gestures as he walks on the course of his golf resort, in Turnberry, Scotland July 14, 2018. Henry Nicholls / REUTERS

The protesters were among the thousands of people who came out in Scotland and England to protest the U.S. president's visit to both countries. Some 10,000 people marched Saturday through the Scottish capital of Edinburgh, while police tried to find a paraglider who breached a no-fly zone and flew a protest banner over the resort in western Scotland where Mr. Trump and his wife, Melania, are staying through Sunday. Anti-fascist groups and political activists were joined by others waving an array of makeshift anti-Trump banners who said they had never demonstrated before. Some signs of their said "We Shall Over Comb" and "Dump Trump."

The glider carried a banner that said "Trump: Well Below Par" over Mr. Trump's resort Friday night to protest his environmental and immigration policies.

Scores of anti-Trump protesters also turned out in London during Mr. Trump's visit to England earlier this week.

In Saturday's tweets, Mr. Trump cast blame on former President Barack Obama for failing to stop Russian election meddling. It was Mr. Trump's first personal response to indictments announced Friday in Washington against the 12 Russian military intelligence officers who allegedly hacked into the presidential campaign of Hillary Clinton, Trump's Democratic rival, and the Democratic Party, and released tens of thousands of emails in a sweeping Kremlin conspiracy to help Mr. Trump win the 2016 election.

"The stories you heard about the 12 Russians yesterday took place during the Obama Administration, not the Trump Administration," Trump tweeted, asking why they didn't "do something about it, especially when it was reported that President Obama was informed by the FBI in September, before the Election?"

The stories you heard about the 12 Russians yesterday took place during the Obama Administration, not the Trump Administration. Why didn’t they do something about it, especially when it was reported that President Obama was informed by the FBI in September, before the Election? — Donald J. Trump (@realDonaldTrump) July 14, 2018

"These Russian individuals did their work during the Obama years. Why didn't Obama do something about it? Because he thought Crooked Hillary Clinton would win, that's why. Had nothing to do with the Trump Administration, but Fake News doesn't want to report the truth, as usual!" the president said in another tweet later in the day.

These Russian individuals did their work during the Obama years. Why didn’t Obama do something about it? Because he thought Crooked Hillary Clinton would win, that’s why. Had nothing to do with the Trump Administration, but Fake News doesn’t want to report the truth, as usual! — Donald J. Trump (@realDonaldTrump) July 14, 2018

The White House had already responded to the news of the indictments in a statement that highlighted how no Americans are charged, and failed to condemn the alleged hacking.

"Today's charges include no allegations of knowing involvement by anyone on the campaign and no allegations that the alleged hacking affected the election result. This is consistent with what we have been saying all along," White House Deputy Press Secretary Lindsay Walters said Friday.

Mr. Trump denies that he or any campaign aides were involved with the Russian campaign. He repeatedly dismisses the ongoing investigation that produced Friday's indictments as a "witch hunt."

Mr. Trump on Saturday also mocked CNN President Jeff Zucker as "Little Jeff Z" and knocked its election coverage following a spat with a CNN correspondent at a news conference Friday in England.

Although Mr. Trump said he plans to raise election meddling with Putin when they meet Monday at the Finnish presidential palace in Helsinki, he has also said he doesn't expect Putin to ever accept blame.

"I will absolutely bring that up. I don't think you'll have any 'Gee, I did it. I did it. You got me,'" Mr. Trump said Friday, referring to Putin, during a press conference with British Prime Minister Theresa May.

The Kremlin, for its part, has dismissed the indictment as incredible, and says it was intended to "spoil" the atmosphere ahead of the Trump-Putin meeting.

"It is regrettable that the circulation of false information in Washington has become the norm, and that criminal cases are brought for obvious political reasons," the Russian Foreign Ministry said Friday.

Leading Democratic senators asked Mr. Trump in a letter Saturday to scrap the summit "if you are not prepared to make Russia's attack on our election the top issue you will discuss."

Meanwhile, Sen. John McCain, a leading Republican senator and Trump critic, has said Mr. Trump must hold Putin accountable or else he should not proceed with the meeting.

"President Trump must be willing to confront Putin from a position of strength and demonstrate that there will be a serious price to pay for his ongoing aggression towards the United States and democracies around the world," McCain said in a statement. "If President Trump is not prepared to hold Putin accountable, the summit in Helsinki should not move forward."