In Vacco v. Quill, the US Supreme Court, in its June 26, 1997 ruling (9-0) stated:

“Even as the States move to protect and promote patients’ dignity at the end of life, they remain opposed to physician assisted suicide.

New York is a case in point. The State enacted its current assisted suicide statutes in 1965. Since then, New York has acted several times to protect patients’ common law right to refuse treatment… In so doing, however, the State has neither endorsed a general right to ‘hasten death’ nor approved physician assisted suicide. Quite the opposite: The State has reaffirmed the line between ‘killing’ and ‘letting die’…

This Court has also recognized, at least implicitly, the distinction between letting a patient die and making that patient die. In Cruzan v. Director, Mo. Dept. of Health (1990), we concluded that ‘[t]he principle that a competent person has a constitutionally protected liberty interest in refusing unwanted medical treatment may be inferred from our prior decisions,’ and we assumed the existence of such a right for purposes of that case. But our assumption of a right to refuse treatment was grounded not, as the Court of Appeals supposed, on the proposition that patients have a general and abstract ‘right to hasten death,’ but on well established, traditional rights to bodily integrity and freedom from unwanted touching. In fact, we observed that ‘the majority of States in this country have laws imposing criminal penalties on one who assists another to commit suicide.'”

June 26, 1997 - Vacco v Quill