Outwardly, Trump has remained receptive to — even enthusiastic about — the prospect of sitting before Mueller, who is investigating whether his campaign colluded with Russia and whether Trump attempted to short-circuit the investigation itself. He has indicated that sitting for an interview himself could help bring the investigation to a swift end.

Privately, however, Trump has been more equivocal about answering Mueller’s questions, depending on the day. Trump has wavered on his pledge as friends and advisers caution him of the risks of speaking to prosecutors who have already charged 19 individuals with criminal offenses, including lying.

The terms of how Trump would be questioned — including whether he would speak under oath — have not yet been determined. Even if he isn’t questioned under oath, however, Trump could still open himself to charges if he lies to Mueller’s team, since lying to the FBI is a crime.