Work on Lapsset, which stands for the “Lamu–South Sudan–Ethiopia Transport Corridor Project”, is expected to begin in 2025.

The plan is to build a high-speed electric railway from Lamu to the town of Isiolo, about 200km northeast of Nairobi. The line would then split into three to connect with Nairobi, Addis Ababa, and the South Sudanese capital of Juba.

Lapsset is expected to cost $13.8bn, greatly exceeding in scale Kenya’s other major rail scheme, the SGR line that connects Mombasa with Nairobi.

However, the Lapsset Authority told the Bloomberg news agencythat the project had an expected internal rate of return greater than 12%, suggesting high confidence in its viability.

Kenya is now seeking $9m from the African Union Infrastructure Fund to finance feasibility studies to assess the technical and economic case for the line.

Kenyan transport minister Kipchumba Murkomen said earlier this month that he would work with Ethiopian ministers to seek joint funding for the project.

The deal came a month after Kenya and Uganda signed a similar agreement to jointly raise $6bn to fund the construction of the extension of the SGR from Naivasha in Kenya to the Ugandan capital of Kampala.