Special counsel Robert Mueller is set to speak with longtime Donald Trump aide and White House Communications Director Hope Hicks, marking a new phase in his department’s investigation into the 2016 presidential election and possible collusion with the Trump campaign.

As Politico reports, Mueller’s team has interviewed firmer Trump aides, including Reince Priebus and Sean Spicer, but Hicks is the first current administration official to be grilled by the special counsel. The interview will take place after Trump returns from his scheduled trip to Asia.

“Nothing about recent events alters the White House’s commitment to fully cooperate with the office of the special counsel,” White House lawyer Ty Cobb told Politico.