The union was recognized by France, United Kingdom, Italy, and Japan in the Treaty of Paris of 1920, which however never came into force, because Japan did not ratify it. The United States refused to sign the treaty on the grounds that Russia was not represented at the Conference. The US also considered Bessarabia a territory under Romanian occupation, rather than Romanian territory, despite existing political and economic relations between the US and Romania. Soviet Russia (and later, the USSR) did not recognize the union, and by 1924, after its demands for a regional plebiscite were declined by Romania for the second time, declared Bessarabia to be Soviet territory under foreign occupation. On all Soviet maps, Bessarabia was highlighted as territory not belonging to Romania.