Trump ya bayyana wannan zabin ne jim kadan bayan ya bayyana gaban taron jamaa bayan zabe a Cincinnati a jihar Ohio a jiya alhamis da daddare. A lokacin ne ya bayyana a sarari cewa ga wanda ya zaba domin ya rike wannan mukamin bayan wasu rahotannin da suka fito daga kafofin yada labarai wadanda basu tabbacin hakan.
Mattis dan shekaru 66, da kuma ake wa lakabi da mahaukacin kare, saboda yawan kalamansa na son yaki, tsohon kwamandan sojan ruwa ne wanda ya jagoranci yakin da aka yi tsakanin Afghanistan da Iran.
Ya jagoranci bataliyan sojojin ruwa lokacin yakin gulf lokacin da aka mamaye kasar Iraqi a shekarar 2003, sai a cikin sahekarar 2010 aka nada shi ya zama babban kwamandan sojojin ruwa na Amurka mai kula da rundunar tsakiya.