Rwanda and Tanzania are weighing up the option of extending the proposed joint standard gauge railway to Rubavu at the border with DR Congo.
The development is part of the outcomes of Tuesday's meeting between the Ministers responsible for transport in Rwanda and Tanzania, officials said.
Extending the railway line to Rubavu would boost commerce between Rwanda and DR Congo.
DR Congo is increasingly becoming a strategic trading partner for Rwanda.
According to statistics from the central bank, Rwanda's informal cross-border exports are dominated trade with DR Congo.
The central bank says that Rwanda recorded an informal cross border trade surplus of $51.9 million in the first six months, up from $36.4 million in the same period last year.
Informal exports, which account for 13.6 per cent of total formal exports, are dominated by exports to DR Congo with a big share of 86.2 per cent of the total informal exports, according to the central bank's latest monetary policy and financial stability statement.
The $2.5 billon Isaka-Kigali railway is estimated to cover 571 kilometres. Extending it to Rubavu would mean stretching it by an extra 144 kilometre, which would mean more costs.
On Tuesday, Claver Gatete, the Minister for Infrastructure and his visiting Tanzanian counterpart Isaac Kamwelwe discussed the available funding options for the project.
In a joint statement, the ministers reiterated their commitment to realise the implementation of the project to reduce transport costs, foster physical integration of transport modes, and improve social services, among others.