The document, which was sent to Corps Commander Mohamed Hamdan Dagalo on November 6, stated that there were 1,200 Sudanese mercenaries ready to move from a military camp in Sudan's Niyala to the Jufra military base in central Libya, Anadolu Agency reported.
The agency said that it could not verify the document, but stressed that security sources confirmed its credibility.
The security sources said that a meeting between Emirati authorities and Dagalo was recently held in Khartoum, during which the UAE proposed financial and military support to Dagalo in return for sending two brigades of Sudanese mercenaries to Libya.
Dagalo reportedly ordered his troops in Southern Darfur to get ready on October 23.
On December 3, the United Nations said 20,000 foreign mercenaries were in Libya causing a "serious crisis".
Speaking at an online meeting of the Libyan Political Dialogue Forum, UN Acting Envoy for Libya Stephanie Williams said, "That is a shocking violation of Libyan sovereignty … a blatant violation of the arms embargo."