Sudan has to terminate all business ties with North Korea before any talks could begin for removing Khartoum from the US terrorism sponsoring list, a top US official said Monday. Sudanese officials have been pushing to remove Sudan from the blacklist, but Washington insists Khartoum must provide a complete assurance it has cut relations with Pyongyang prior to any negotiation. Even though there are no diplomatic relations between Sudan and North Korea, rights organization confirmed military cooperation between them. "Above all is the importance of terminating any business ties to North Korea," a top US official familiar with Washingtons negotiations with Khartoum told AFP on condition of anonymity. He indicated that the evidence provided to Washington has to confirm that the business has been terminated. Khartoum says it is committed to respecting all resolutions passed by the UN Security Council against North Korea, but the US still wants assurances that ties are completely cut between the two. "No more business, period. Give us the evidence that in fact you are stopping it. Thats what they have to do with us," he asserted. Last week, Sudanese foreign ministry issued a statement confirming it has "no relations with Democratic Peoples Republic of Korea at any level." This escalation is months after Washington lifted decades of trade embargo and economic sanctions imposed over Sudans alleged support of extremist groups, but kept Sudan in its list of "state sponsors of terrorism." Sudan hopes the second phase of the Sudanese-US talks will lead to removing its name from the list, otherwise international banks would be wary of doing business with Sudanese banks. This will in turn hamper an economic revival in the African country as it struggles with surging inflation, high debt and the loss of oil earnings. Sudans overall economy received a hard blow after the South separated from the North in 2011, taking with it about 75 percent of oil earnings. With a foreign debt of more than $50 billion and a plunging pound against the dollar because of an acute shortage of foreign currency, the economic revival that Sudan was expecting after lifting of the sanctions did not happen.