thumb|Armée nationale congolaise (ANC) armoured vehicles during the Congo Crisis On 14 July 1960, in response to requests by Prime Minister Lumumba, the UN Security Council adopted United Nations Security Council Resolution 143. This called upon Belgium to remove its troops and for the UN to provide military assistance to the Congolese forces to allow them "to meet fully their tasks". Lumumba demanded that Belgium remove its troops immediately, threatening to seek help from the Soviet Union if they did not leave within two days. The UN reacted quickly and established the United Nations Operation in the Congo (ONUC). The first UN troops arrived the next day but there was instant disagreement between Lumumba and the UN over the new force's mandate. Because the Congolese army had been in disarray since the mutiny, Lumumba wanted to use the UN troops to subdue Katanga by force. Lumumba became extremely frustrated with the UN's unwillingness to use force against Tshombe and his secession.Oliver Ramsbotham, Tom Woodhouse, Encyclopedia of International Peacekeeping Operations, (ABC-CLIO: 1999), p. 54 . He cancelled a scheduled meeting with Secretary General Dag Hammarskjöld on 14 August and wrote a series of angry letters instead.Hobbs, Nicole, "The UN and the Congo Crisis of 1960" (2014). Harvey M. Applebaum '59 Award. To Hammarskjöld, the secession of Katanga was an internal Congolese matter and the UN was forbidden to intervene by Article 2 of the United Nations Charter. Disagreements over what the UN force could and could not do continued throughout its deployment.
thumb|Armée nationale congolaise (ANC) armoured vehicles during the Congo Crisis On 14 July 1960 in response to requests by Prime Minister Lumumba the UN Security Council adopted United Nations Security Council Resolution 143 This called upon Belgium to remove its troops and for the UN to provide military assistance to the Congolese forces to allow them "to meet fully their tasks" Lumumba demanded that Belgium remove its troops immediately threatening to seek help from the Soviet Union if they did not leave within two days The UN reacted quickly and established the United Nations Operation in the Congo (ONUC) The first UN troops arrived the next day but there was instant disagreement between Lumumba and the UN over the new force's mandate Because the Congolese army had been in disarray since the mutiny Lumumba wanted to use the UN troops to subdue Katanga by force Lumumba became extremely frustrated with the UN's unwillingness to use force against Tshombe and his secessionOliver Ramsbotham Tom Woodhouse Encyclopedia of International Peacekeeping Operations (ABC-CLIO 1999) p 54  He cancelled a scheduled meeting with Secretary General Dag Hammarskjöld on 14 August and wrote a series of angry letters insteadHobbs Nicole "The UN and the Congo Crisis of 1960" (2014) Harvey M Applebaum '59 Award To Hammarskjöld the secession of Katanga was an internal Congolese matter and the UN was forbidden to intervene by Article 2 of the United Nations Charter Disagreements over what the UN force could and could not do continued throughout its deployment