Karine Jean-Pierre says President Biden made a surprise nighttime visit to Hallie Biden's

JUST IN: White House Karine Jean-Pierre says President Biden made a surprise nighttime visit to Hallie Biden's Delaware home on Sunday, shortly before she is set to testify as a key witness in Hunter Biden's federal gun crimes trial because of 'the upcoming 9th anniversary of his son Beau Biden's passing.' She said it had nothing to do with claims of witness tampering.

NOTE: The brief private visit took place around 8 p.m., eight days before the trial, which starts on June 3. Hallie, who dated Hunter during the time of the alleged crimes, is one of a dozen expected witnesses.

Journalist: Why did President Biden have a private meeting with a witness who plans to testify in court against his son?

Karine Jena-Pierre: Can you say more?

Journalist: Hallie Biden is a key government witness who allegedly disposed of a gun that Hunter is accused of buying illegally. President Biden was at her house this week.

Karine Jean-Pierre: "The American people should also be told the full breadth of this, not just a part of this question here. As you all know, the president actually spoke to this yesterday during his Memorial Day address where he talked about the passing, the anniversary, the 9th anniversary of the passing of his son. He visited her as that anniversary is approaching. She is family, as she was married to his late son. They did not talk about her testimony; this visit was about the upcoming 9th anniversary of his son's passing." WATCH