| Country | Action | Action Date | Effective Date |
|---|---|---|---|
| BULGARIA | Acceptance | 21/08/1972 | |
| CANADA | Acceptance | 15/09/1961 | |
| CUBA | Adherence | 28/11/1975 | |
| DENMARK | Definitive Signature | 24/04/1961 | |
| FRANCE | Definitive Signature | 24/04/1961 | |
| GERMAN DEMOCRATIC REPUBLIC | Adherence | 21/05/1974 | |
| GERMANY FEDERAL REPUBLIC | Definitive Signature | 24/04/1961 | |
| ICELAND | Definitive Signature | 24/04/1961 | |
| ITALY | Acceptance | 14/09/1961 | |
| JAPAN | Acceptance | 01/07/1970 | |
| NORWAY | Definitive Signature | 24/04/1961 | |
| POLAND | Acceptance | 05/06/1963 | |
| PORTUGAL | Definitive Signature | 24/04/1961 | |
| ROMANIA | Acceptance | 21/03/1967 | |
| SOVIET UNION | Definitive Signature | 24/04/1961 | |
| SPAIN | Definitive Signature | 24/04/1961 | |
| UNITED KINGDOM | Signature | 24/04/1961 | |
| UNITED KINGDOM | Definitive Signature | 24/04/1961 | |
| UNITED STATES OF AMERICA | Signature | 24/04/1961 | |
| UNITED STATES OF AMERICA | Acceptance | 09/02/1962 |