The move was criticised by the opposition, which accused the government of being "paranoid".
Foreign affairs minister Henry Okello Oryem said Uganda had developed "vibrant" internal bodies such as the Uganda Human Rights Commission.
The East African country has however seen a series of crackdowns on those opposed to Museveni's 36-year rule.
Kampala
Uganda said Wednesday it would not renew its mandate for the UN's rights office, a move criticised in a country where campaigners say freedoms are regularly threatened.
The move means that the rights monitor's Kampala office will close down when its authorisation expires this year.
"Our human rights record over the years has tremendously improved under our able leadership of President (Yoweri) Museveni," state minister for foreign affairs Henry Okello Oryem told AFP.
He said Uganda had developed "vibrant" internal bodies such as the Uganda Human Rights Commission and civil society groups which monitored its human rights performance.
Crackdowns
The East African country has however seen a series of crackdowns on those opposed to Museveni's 36-year rule, with journalists attacked, lawyers jailed, and opposition leaders violently muzzled.
In November last year, the UN's Committee Against Torture voiced its concern about reports that "torture and ill-treatment continued to be frequently practised in the country".
It also called for Uganda to abolish the use of unauthorised places of detention described as "safe houses".
'Stumbling block'
Uganda wrote to the Office of the UN High Commissioner for Human Rights (OHCHR) on February 3 to announce it would not be renewing the mandate beyond its current term.
The letter, seen by AFP, said the move reflected "the strong government commitment to the promotion and protection of human rights, the prevailing peace throughout the country coupled with strong national human rights institutions and a vibrant civil society with the capacity to monitor the promotion and protection of human rights throughout the country".
Seif Magango, a spokesman for the OHCHR, told AFP that the Ugandan government had taken "a unilateral decision" on the issue.
"Discussions are ongoing with the Ugandan authorities," he said.
‘Paranoid’
The move was criticised by the opposition, which accused the government of being "paranoid".
"It's not surprising they are not renewing the mandate of the UN office because they fear strict observance of human rights," saidshadow foreign minister Muwada Nkunyingi of the National Unity Platform.Â
"The government wants to violate human rights unhindered and this office is seen as a stumbling block to their evil intentions towards Ugandans," he added.
The National Unity Platform is led by Robert Kyagulanyi, also known as Bobi Wine, who unsuccessfully challenged Museveni in the January 2021 election and has often been targeted by security forces.
The UN office was in the spotlight that year when security forces beat up a group of political activists who had gone there to petition the body over alleged rights violations after the polls.Â
Journalists covering the demonstration were roughed up, several injured and their equipment briefly confiscated before the then head of the military, David Muhoozi, apologised.
The UN rights office in Kampala was initially set up in 2005 and its mandate has previously been renewed every few years.