Uganda has denied reports that it abandoned Kenya Foreign Affairs Cabinet Secretary Amina Mohamed during elections for chairperson of the African Union Commission in Addis Ababa on Monday.
Ms Mohamed lost to Chadian foreign minister Moussa Faki Mahamat after seven rounds of voting.
A local daily on Tuesday quoted South Sudan ambassador to Ethiopia James Morgan claiming Uganda withdrew its backing because Kampala was not happy with the way Nairobi wanted "everything".
But the Uganda foreign affairs ministry on Wednesday said the claims were "unsubstantiated".
"Uganda wishes to state categorically that our support to the candidature of Amina before and during elections was unequivocal," it said in a statement.
President Yoweri Museveni, the statement said, backed Ms Mohamed because of the close bilateral ties Kampala shares with Nairobi.
"Ambassador Amina Mohamed was (also) endorsed as the East African Community candidate," the ministry said.
Despite the loss, Kampala pledged deeper working ties with Nairobi and assured Ms Mohamed of its support in the future.
"Uganda wishes to reassure the government and the people of Kenya, and Amina in particular, that we remain a reliable ally and partner given our warm and close relations and our commitment to the EAC integration," the statement read.
Uganda is the biggest importer of Kenyan goods and the two countries are partners in the fight against Al-Shabaab in Somalia.
President Museveni and President Uhuru Kenyatta are also personal and political friends, with Deputy President William Ruto campaigning for the Ugandan leader in the last elections.
President Museveni also joined Mr Kenyatta in condemning the Kenyan opposition's support for the International Criminal Court, which had charged Kenyan leaders with crimes against humanity.
'FRIEND OR THREAT?'
Uganda's reaction follows Ms Mohamed's call on Tuesday to the Kenyan government to re-evaluate its neighbours.
The re-evaluation, she said, should establish why neighbouring countries, whom she did not name, decamped to vote for other candidates in the Monday election.
"Are we seen as a friend or a threat?" she told journalists in Addis Ababa, adding that "appearances are deceptive."
"I think we are very honest people, so it is difficult to deal with deceptive people. Going forward, it is a good lesson to learn.
Tanzania, which is also suspected of withdrawing its support for Ms Mohamed, denied the claims on Wednesday on BBC radio's Kiswahili Service.
The other countries suspected of abandoning Ms Mohamed are Burundi and Djibouti.
The other candidates who lost the race are Senegal's Abdoulaye Bathily, Pelonomi Moitoi of Botswana and Agapito Mokuy of Equatorial Guinea.