Siraj Ahmad Khan assumed the position of High Commissioner of Islamic Republic of Pakistan to United Republic of Tanzania in March 2023. Prior to his appointment as High Commissioner, he served as Director General (China) in the Ministry of Foreign Affairs in Islamabad.

Siraj has worked at various positions in Pakistan Missions abroad. He has served as Counsellor in Pakistan Embassy in Beijing from July 2015-2018, focusing on bilateral relations and CPEC. From July 2012 till July 2015, he worked as First Secretary in Pakistan Embassy in Warsaw, dealing with bilateral relations. He also served as Third Secretary in Embassy of Pakistan, Tokyo from September 2006 till November 2009, where he worked on bilateral relations, economic issues as well as community matters.

He has served at the Ministry of Foreign Affairs, Islamabad as Assistant Director Europe (2004-2005), Protocol Officer (2006), Deputy Director Europe (2009-2011), Director Europe (2011-2012), Director CPEC, Director Afghanistan (2018-2019) and Director General Europe, Africa and China (2020-2023). 

Siraj holds a degree in M.Sc (Honours) in Rural Development from Agricultural University of Peshawar in 2003. He also studied Japanese language from October 2005 till June 2006 in Kansai Institute in Osaka. He joined the Foreign Service of Pakistan in July 2003.