Idara ya mambo ya nje inachukua jukumu la mambo yote ya nje, yanayohusiana na mahusiano ya dola ya Khilafah na dola za kigeni, bila kujali mambo haya na mahusiano haya ni yapi. Iwe yanahusiana na upande wa kisiasa na yale yanayojumuisha, kama vile kuunda mikataba, mikataba ya amani, kusitisha mapigano, mazungumzo, kuteua mabalozi, kutuma Wajumbe na wawakilishi, na kuanzisha ubalozi na konseli. Pia inajumuisha mahusiano yanayohusiana na mambo ya kiuchumi, kilimo na biashara, pamoja na mawasiliano ya posta au mawasiliano ya waya na yasiyo na waya, n.k. Idara ya mambo ya nje inasimamia mambo haya yote, kwa kuwa yanahusika na mahusiano ya dola ya Khilafah na nchi nyingine.

The foreign affairs department undertakes the responsibility of all foreign affairs, pertaining to the relations of the Khilafah state with the foreign states, whatever these affairs and relations may be. Whether they are related to the political aspect and what it entails like the formation of pacts, peace treaties, cease-fires, negotiations, appointing ambassadors, sending Messengers and delegates, and establishing embassies and consulates. It also includes relations, which are related to economical, agricultural, and trading matters as well as postal communications or wire and wireless communications etc. The foreign affairs department runs all these matters, because they are concerned with the relations of the Khilafah state with other states.

Mtume (ﷺ) alianzisha mahusiano ya kimataifa na nchi nyingine na mataifa mengine. Alimtuma 'Uthman bin 'Affan ili kujadiliana na Quraysh, kama vile yeye mwenyewe alivyofanya mazungumzo na wajumbe wa Quraysh. Alituma wajumbe kwa wafalme, na alipokea wajumbe wa wafalme na viongozi. Pia alifanya mikataba na mapatano ya amani. Vivyo hivyo baada yake, Makhalifa wake walikuwa wakianzisha mahusiano ya kisiasa na nchi nyingine na mataifa mengine. Walikuwa wakiwateua watu wa kutekeleza vitendo hivyo kwa niaba yao, kwa msingi kwamba kitendo chochote ambacho mtu anaweza kukitekeleza mwenyewe, anaweza kukimkabidhi mtu mwingine ili akitekeleze kwa niaba yake.

The Messenger (pbuh) established foreign relations with other states and entities. He sent ‘Uthman bin ‘Affan to negotiate with Qur’aysh just as He negotiated with the delegates of Qur’aysh. He sent delegates to Kings and He received the delegates of Kings and leaders. He also concluded pacts and peace treaties. Similarly after him, his Khulafaa’ used to establish political relations with other states and entities. They used to appoint people to carry out these actions on their behalf, on the basis that whatever an action a person can perform by himself, He can delegate it to some other person to carry out it on his behalf.