Uganda has denied accusations that it did not back Kenya's Foreign Minister Amina Mohamed in her bid to become chairperson of the African Union Commission.
Ms Mohamed, who was seen as a frontrunner, accused neighbouring countries in her concession speech, of being "deceptive" and called for an investigation.
Kenyan media reports said that Uganda, Burundi and Djibouti did not vote for Ms Mohamed in the final round clearing the path for Moussa Faki Mahamat, Chad's foreign minister.
Mr Mahamat secured a two-thirds majority, 36 votes, to be declared winner.
Kenya's government reportedly spent $3 million in its campaign rallying support for Ms Mohamed.
By tradition, the post rotates between Anglophone and Francophone countries. Outgoing head Nkosazana Dlamini-Zuma, from English-speaking South Africa, succeeded French-speaking Jean Ping in 2012.
Uganda accused the media, in a statement, of baseless assertions, questioning its commitment to Ms Mohamed, who had been endorsed by the East African Community for the post.
"Uganda wishes to state categorically that our support for the candidature of Amina Chawahir Mohamed, before and during elections, was unequivocal," the Ministry of Foreign Affairs said in the statement.