The top Democrat on the Senate Intelligence Committee says the panel has requested documents from Donald Trump Jr.
Virginia Sen. Mark Warner said the committee requested the documents "as recently as this week," after President Donald Trump's son released emails in which he appeared eager to accept Russian government information that could damage Hillary Clinton's campaign.
Warner has said he wants Trump Jr. to testify. The president's son tweeted Monday that he would work with the panel.
Trump's son-in-law, Jared Kushner, is also expected to testify in closed session. Warner said they are still waiting to receive some documents from Kushner.
Warner said the panel "is just now starting to interview those individuals who are affiliated with the Trump campaign who may or may not have had contacts with Russians."