State Date of signature Date of receipt of the instrument of ratification or accession Turkey Turkmenistan Uganda Ukraine United Kingdom of Great Britain and Northern Ireland 25 January 1988 2 August 1988 25 June 1999a 3 November 1986a 24 February 1987 8 December 1988 United States of America Uruguay Uzbekistan Venezuela Yemen 18 April 1988 4 February 1985 Zambia a Accession. b Succession. 104 27 February 1986 15 March 1985 15 February 1985 21 October 1994 24 October 1986 28 September 1995a 29 July 1991 5 November 1991a 7 October 1998a