She reiterated that the "real collusion scandal" involves the Clinton campaign, Fusion GPS and Russian Federation working to "smear" Trump.
Papadopoulos, who is 30 years old, joined the Trump campaign in early March 2016 as a foreign adviser.
Former Trump campaign chairman Paul Manafort and his associate Rick Gates were indicted by a federal grand jury Monday on 12 counts, including conspiracy against the United States, conspiracy to launder money, unregistered agent of a foreign principal, false and misleading Foreign Agent Registration (FARA) statements, false statements and seven counts of failure to file reports of foreign banks and financial accounts.
Sanders insisted that Papadopoulos was a member of a volunteer advisory council that only met once and had no paid role within the campaign, while glossing over the actual meeting that occurred between even higher campaign officials and Russian government officials in Trump Tower in June 2016.
Sanders said during Monday's White House press briefing that Papadopoulos was simply a "volunteer" like "thousands" of others during the campaign.
Trump's plan doesn't include the phase in, she said.
Non-profit publishes study showing many baby foods contaminated
It also stated that some products labelled certified organic had higher amounts of mercury and lead than conventional baby foods. Of the products that claim to be BPA-free, 60 percent were found positive for the industrial chemical bisphenol A .
Sanders was then asked by a reporter: "So his activities were entirely of his invention, no one asked him to do any of these things - is that what you're telling the American public?"
Mrs. Sanders said that the Trump campaign has always fully cooperated with the investigation, including turning over all of Mr. Papadopoulos's emails.
She also criticized Hillary Clinton's campaign and the Democratic National Committee for their contributions which funded research for a dossier alleging Mr. Trump's connections to Russian Federation.
CNN has fact-checked the Trump administration in the past on its chyron.
"We believe that it will be concluded soon", she said.