Dr Fortune Gomo, 39, who was originally from Zimbabwe, was pronounced dead at the scene of the incident on Saturday.
Jama'at Nusrat al-Islam wal-Muslimin (JNIM) is the main group behind a surge in militant jihadist attacks in West African.
Museveni's critics say he has ruled with an iron hand since he seized power as a rebel leader in 1986.
Only one of the eight is from South Sudan.
There will be no state funerals until April 2026 - unless the president decides to make an exception.
The session ended with a call for the global community to take responsibility and act decisively before the crisis worsens.
Majaliwa said his decision was guided by God and he had made it "in good faith".
The helicopter was operated by the Ugandan contingent under the African Union Transitional Mission in Somalia (AUSSOM).
Seven Ghanaian suspects have been arrested in connection with the trafficking.
