Tanzania said the decision was taken in retaliation for Kenya's denial of rights to its own national carrier Air Tanzania to operate cargo flights between the two countries.
In a statement, the Tanzania Civil Aviation Authority said it decided "to rescind the approvals for Kenya Airways to operate passenger flights between Nairobi and Dar es Salaam ... with effect from 22 January 2024."
"This is to reciprocate the decision by the aeronautical authorities of the Republic of Kenya to refuse the Tanzania request for all-cargo flight operations by Air Tanzania Company."
TCAA also said Kenya's decision to decline Air Tanzania's request for cargo flights violated a 2016 Memorandum of Understating between both countries on air services.
In a statement, Kenya Airways said it was aware of the ban on its flights and was engaging aviation authorities in both countries "to find a solution that will ensure there are no flight disruptions between Nairobi and Dar es Salaam."
Kenya Airways is one of Africa's largest airlines. Tanzania, where attractions include mountains and vast wildlife reserves that teem with game, draws more than a million tourists a year, making it one of its biggest markets.
The clash between Tanzania and Kenya adds to a growing number of trade and commercial disputes between members of the East African Community, a regional bloc that operates a customs union.
Kenya has previously complained about cheap products from neighboring Uganda and blocked some, including milk and sugar, drawing protests from Kampala.
Landlocked Uganda has also taken Kenya to a regional court over a dispute related to the importation of petroleum products.
Although Air Tanzania is a small airline, in recent years authorities have been trying to expand its fleet, routes and operations to earn a bigger share of revenues from the region's aviation business.
