It has served as the home of the United Nations Office at Geneva since 1946 when the Secretary - General of the United Nations signed a Headquarters Agreement with the Swiss authorities .
Swiss did not become a member of the United Nations until 2002 .
It has served as the home of the United Nations Office at Geneva since 1946 when the Secretary - General of the United Nations signed a Headquarters Agreement with the Swiss authorities , although Switzerland did not become a member of the UN until 2002 .