Thant began serving as acting Secretary-General from November 3 , 1961 , when he was unanimously appointed by the General Assembly , on the recommendation of the Security Council in Resolution 168 , to fill the unexpired term of Dag Hammarskjöld .
Thant began serving as Acting Secretary-General from November 3 , 1961 , when he was unanimously appointed by the General Assembly , on the recommendation of the Security Council , to fill the unexpired term of Dag Hammarskjöld .