The Intergovernmental Authority on Development (Igad) conference is set to take place in the capital Mogadishu next Saturday.
Heads of State and Foreign Affairs ministers from member countries are expected to attend the meeting, ranked highly among international-level gatherings held in Somalia since 1985.
Sources said the ban was meant to minimise terror threats and decongest Aden Adde International Airport.
In July, two bombs exploded near the main entrance to the airport, close to a base for African Union peacekeeping troops, killing at least 13.
In February, a suspected suicide bomber blew a hole in the fuselage of a Daallo Airlines plane at the same airport, killing at least one.
This latest move is one of many measures Somalia's weak Mogadishu-based government has put in place to secure the conference.
Somali Aviation Minister Ali Ahmed said the decision to keep Kenyan planes out would stand until further notice.
He cited “special consideration” and did give reasons in a letter on Sunday that was copied to the Kenya Civil Aviation Authority, the Interior ministry and other Somalia agencies.
But two semi-autonomous states of Puntland and Somaliland have disowned the order by Mogadishu, saying they will not comply.
Sources in the country said the ban will be lifted after the end of the summit.
Reached for comment, Kenyan Interior ministry spokesperson Mwenda Njoka said: “I think the Somali government should be the one to explain about the ban."
Previous calls, including one by President Hassan Mohamud, have been made for the restriction of miraa trade in Somalia.
The airport receives close to 20 miraa-carrying planes from Nairobi daily and more than 20 tons of the stimulant which are delivered to various parts of the country.
No plane carrying miraa left for the horn of Africa country on Monday, plunging farmers and traders into heavy losses.
Read: Why does Uhuru encourage miraa growing and use?
The conference will focus on Somalia's political stability ahead of its October presidential and parliamentary elections.
Igad member countries are Kenya, Uganda, Sudan, Djibouti, Eritrea, South Sudan and Ethiopia.
Read more: http://www.the-star.co.ke/news/2016/09/06/why-somalia-suspended-kenyas-miraa-planes_c1415672