been the chief advocate of a unified state. Less than a month after the Katangese secession, on 8 August, a section of Kasai Province situated slightly to the north of Katanga also declared its autonomy from the central government as the Mining State of South Kasai () based around the city of Bakwanga. South Kasai was much smaller than Katanga, but was also a mining region. It was largely populated by the Luba ethnic group, and its president, Albert Kalonji, claimed that the secession was largely sparked by persecution of the Baluba in the rest of the Congo. The South Kasai government was supported by , another Belgian mining company, which received concessions from the new state in return for financial support. Without control over Katanga and South Kasai, the central government was deprived of approximately 40 percent of its revenues. Foreign reaction and UN intervention Disquiet about Belgium's support for the secessionist states led to calls within the United Nations (UN) to remove all Belgian troops from the country. The Secretary General of the UN, Dag Hammarskjöld, believed that the crisis would provide the organisation with a chance to demonstrate its potential as a major peacekeeping force and encouraged the sending of a multinational contingent of peacekeepers to the Congo under UN command. On 14 July, the UN Security Council adopted Resolution 143, calling for total Belgian withdrawal from the Congo and their replacement with a UN-commanded force. The arrival of the United Nations Operation in the Congo (ONUC) was initially welcomed by Lumumba and the central government who believed the UN would help suppress the secessionist states. ONUC's initial mandate, however, only covered the maintenance of law and order. Viewing the secessions as an internal political matter, Hammarskjöld refused to use UN troops to assist the central Congolese government against them; he argued that doing so would represent a loss of impartiality and breach Congolese sovereignty. Lumumba also sought the assistance of the United States government of Dwight D. Eisenhower, which refused to provide unilateral military support. Frustrated, he turned to the Soviet Union, which agreed to provide weapons, logistical and material support. Around 1,000 Soviet military advisors soon landed in the Congo. Lumumba's actions distanced him from the rest of the government, especially Kasa-Vubu, who feared the implications of Soviet intervention. The Americans also feared that a Soviet-aligned Congo could form the basis of a major expansion