Radonjić ya ci kwallaye 5 a wasanni 6 tsakanin 2012 da 2013, ciki har da hat-trick a wasan Belarus. Daga baya, ya kuma kasance memba na ƙungiyar ƙasa ta ƙasa da 18 da ƙasa da 19. An kira Radonjić a cikin tawagar 'yan wasan Serbia U20 a watan Nuwamba 2016 ta kocin Nenad Lalatović, lokacin da ya fara bugawa kungiyar wasa a wasan da Montenegro. A matsayinsa na kocin zabin U21 na Serbia, Nenad Lalatović ya kuma gayyace shi zuwa ga tawagar gasar zakarun Turai ta 2017
Ka yi haƙuri. A watan Nuwambar 2017, Mladen Krstajić ya gayyaci Radonjić zuwa tawagar kwallon kafa ta Serbia don yawon shakatawa na Asiya. Ya fara bugawa Serbia wasa a wasan sada zumunta da Koriya ta Kudu a ranar 14 ga Nuwamba, 2017, inda ya maye gurbin Andrija Živković a minti na 81 na wasan.