49-year-old Headley also pleaded not guilty to the charge of plotting terror attacks in Denmark. The next hearing of the case will be held on Jan 12.
He was charged by the FBI on Mon, Dec 7, in a 12-count criminal information with six counts of conspiracy to bomb places in India and Denmark and for providing material support to terrorist plots.
Speaking to reporters, Headley's attorney John Theis said, "David Headley is charged with certain acts arising out of things that happened in Denmark and India. These are very serious charges and we are taking them very seriously. I want to remind everyone that he is presumed innocent of these charges against him."
When asked whether Indian authorities could get a chance to interrogate Headley, Theis said, "That is something we will have to look at. I have no idea of assessing the chances. If they make any such requests, we will look at it when it comes."
Theis futher said over the next several weeks and months he and his co-counsel Robert Seeder would review evidence and allegations against Headley.
"I expect that there will be a lot of material that we will be going through in preparing our defence in this case," he added.