The Republican president says Wiles plans to begin treatment immediately but makes no suggestion she's pulling back on her work as one of his closest advisers.
Some Democrats are threatening this week to force a series of votes on the war, hoping that the efforts to gum up the Senate's voting schedule will prod Republicans to action.
The comments came during a three-minute phone call Monday morning with PBS News' Liz Landers, while the president was attending what he described as a "very important meeting" on the Iran war.
President Donald Trump has grown more agitated with news coverage and has failed to explain the Iran war -- or how it will end -- in a way that resonates with the American public.