State party Date of receipt of the instrument of ratification* accession a/ or succession b/ Date of entry into force Netherlands New Zealand Nicaragua Niger Norway 11 28 12 7 13 December 1976 December 1978 March 1980 a/ March 1986 a/ September 1972 11 28 12 7 23 March 1979 March 1979 June 1980 June 1986 March 1976 Panama Paraguay Peru Philippines Poland 8 10 28 23 18 March 1977 June 1992 a/ April 1978 October 1986 March 1977 8 10 28 23 18 June 1977 September 1992 July 1978 January 196? June 1977 Portugal Republic of Korea Romania Russian Federation Rwanda 15 10 9 16 16 June 197S April 1990 £/ December 1974 October 1973 April 1975 a/ 15 10 23 23 23 September 1978 July 1990 March 1976 March 1976 March 1976 Saint Vincent and the Grenadines San Marino Senegal Seychelles Slovenia 9 18 13 5 6 November 1981 a/ October 1985 £/ February 1976 May 1992 a/ July 1992 b/ 9 18 13 5 6 February 1982 January 1986 May 1978 August 1992 July 1992 Somalia Spain Sri Lanka Sudan Suriname 24 27 11 18 28 January 1990 a/ April 1977 June 1980 £/ March 1986 a/ December 1976 a/ 24 27 11 18 28 April 1990 July 1977 September 1980 June 1986 March 1977 Sweden Switzerland Syrian Arab Republic Togo Trinidad and Tobago 6 18 21 24 21 December 1971 June 1992 a/ April 1969 a/ May 1984 a/ December 1978 a/ 23 18 23 24 21 March 1976 September 1992 March 1976 August 1984 March 1979 Tunisia Ukraine United Kingdom of Great Britain and Northern Ireland United Republic of Tanzania 18 March 1969 12 November 1973 23 March 1976 23 March 1976 20 May 1976 11 June 1976 a/ 20 August 1976 11 September 1976 United States of America Uruguay Venezuela Viet Nam Yemen 8 1 10 24 9 8 23 10 24 9 June 1992 April 1970 May 1978 September 1982 a/ February 1987 a/ -168- September 1992 March 1976 August 1978 December 1982 May 1987