Wikipedia tells the interesting story of this UN Covenant that the US signed in 1979 (under President Carter) but has not ratified, yet. Explanation below.
Amnesty International writes that "The United States signed the Covenant in 1979 under the Carter administration but is not fully bound by it until it is ratified. For political reasons, the Carter administration did not push for the necessary review of the Covenant by the Senate, which must give its 'advice and consent' before the US can ratify a treaty. The Reagan and George H.W. Bush administrations took the view that economic, social, and cultural rights were not really rights but merely desirable social goals and therefore should not be the object of binding treaties. The Clinton Administration did not deny the nature of these rights but did not find it politically expedient to engage in a battle with Congress over the Covenant. The George W. Bush administration followed in line with the view of the previous Bush administration." The Obama Administration stated "The Administration does not seek action at this time" on the Covenant. The Heritage Foundation, a critical conservative think tank, argues that signing it would obligate the introduction of policies that it opposes such as universal health care.