Contracting Party |
Accession Date |
Withdrawal Date |
| United States of America |
1 September 1949 |
31 December 1976 |
| United Kingdom |
15 December 1949 |
31 December 1978 |
| Iceland |
13 February 1950 |
|
| Canada (Including Newfoundland) |
3 July 1950 |
|
| Denmark |
4 December 1950 |
31 December 1978 |
| Spain |
17 January 1952 |
|
| Norway |
3 July 1952 |
|
| Portugal |
19 July 1952 |
|
| Italy |
19 August 1952 |
31 December 1978 |
| France |
27 January 1953 |
31 December 1978 |
| Federal Republic of Germany |
27 January 1953 |
31 December 1978 |
| Union of Soviet Socialist Republics (USSR) |
10 April 1958 |
|
| Poland |
21 November 1961 |
|
| Romania |
21 March1967 |
|
| Japan |
1 July 1979 |
|
| Bulgaria |
21 August 1972 |
|
| German Democratic Republic |
21 May 1974 |
|
| Republic of Cuba |
28 November 1975 |
|