In Washington v. Glucksberg, the US Supreme Court declared in its June 26, 1997 ruling (9-0):

“The history of the law’s treatment of assisted suicide in this country has been and continues to be one of the rejection of nearly all efforts to permit it. That being the case, our decisions lead us to conclude that the asserted ‘right’ to assistance in committing suicide is not a fundamental liberty interest protected by the Due Process Clause. “

June 26, 1997 - Washington v. Glucksberg