On 23 July 2010, Djibouti and Guinea pledged troops to AMISOM. On 17 September 2010, an AU envoy said in Nairobi that AMISOM's size had grown from 6,300 to 7,200 troops after an additional battalion from Uganda joined the force. In December 2010, the UN backed AMISOM in increasing the mission's authorised size to 12,000 – UN Security Council resolution 1964 of 22 December 2010 – and at the same time reports indicated that Uganda had promised an extra 1,800 personnel, with Burundi an extra 850.