said in a letter that it would not provide some documents about flynn because they were outside the scope of the committee's inquiry, but the white house won't say if flynn broke the law. >> i don't know what he filled out or did or did not do. >> reporter: the top democrat in the senate declined to rule out pushing for a subpoena to force flynn to testify. >> these are extremely, extremely troubling allegations today. >> reporter: will it be necessary to issue a subpoena? >> well, we'll see. >> reporter: and the gop chairman of the senate intelligence committee says the panel wants to question flynn. flynn's role also expected to be highlighted next month when a senate panel hears testimony from former obama justice official sally yates who privately warned trump officials that flynn could be susceptible to russian blackmail. what about sally yates and her allegedly saying michael flynn could be subject to russian blackmail? >> we'll ask her all questions about russia what, she knew about trump ties. was there any administration