President Donald Trump said Tuesday that the Justice Department would not end its investigation into Federal Reserve Chairman Jerome Powell over cost overruns tied to renovations at the central bank’s headquarters, even as the inquiry threatens to complicate his effort to install a successor.

During an appearance on CNBC’s Squawk Box, the president was asked whether he would consider ending the DOJ investigation to expedite the nomination of Kevin Warsh, his pick to replace Powell as chairman of the Federal Reserve Board of Governors. Trump defended the investigation, saying it was important to know how the cost overruns happened under the watch of Powell, who Trump referred to by the nickname “Too Late.”