"It's on", spokeswoman Sarah Sanders said.
White House press secretary Sarah Sanders on Friday said the summit was still moving forward and there were no plans to cancel it. There is no allegation in this indictment that any American citizen committed a crime.
He doubled down on that sentiment on Friday, urging Trump to hold the Russian president "accountable".
The charges put an even greater spotlight on Trump's treatment of Putin, who has denied making efforts to intervene in the USA election that Trump, a Republican, unexpectedly won.
Similarly, Sen. Mark Warner, the top Democrat on the Senate Intelligence Committee, said Trump should cancel the meeting and that it should not be in a one-on-one setting.
"The United States' commitment to North Atlantic Treaty Organisation remains very strong", Trump said during the surprise news conference.
Two NATO sources said, however, that Trump had not issued a threat to pull the United States out of the alliance that it helped found to keep the peace in Europe after World War Two.
The prime minister said that she "welcomed" Trump's meeting with Russian President Vladimir Putin, which is to take place on Monday in Helsinki, Finland. "But I will absolutely, firmly ask the question", he added.
But he later referred to the Russian Federation investigation as "rigged" and a "witch hunt", despite Rosenstein saying he briefed the president on the developments earlier in the week.
Defense Secretary Jim Mattis and national security adviser John Bolton, at least prior to joining the White House, have both been more critical of Moscow than the president they serve.
According to a tweet from Bloomberg White House reporter Jennifer Epstein, the Trump-Putin summit is now still a go.
Rosenstein called for unity in the face of Russian meddling.
"It was important for the president to know what information we've uncovered because he's got to make very important decisions for the country", Rosenstein said.
"The conspirators covertly monitored the computers of dozens of DCCC and DNC employees, implanted hundreds of files containing malicious computer code, and stole emails and other documents", it said.
By June 2016, the defendants began planning the release of tens of thousands of stolen emails and documents, the indictment alleges.
Others in the room, including the Lithuanian president whose country is among the most nervous of Russian ambitions, denied a suggestion that Trump had threatened to quit the alliance.
Mueller previously indicted 13 Russians and three companies for allegedly interfering in the presidential vote.