The expansion of the 25km stretch from the James Gichuru Road-Waiyaki Way junction to Rironi Road has stalled due to lack of funds to pay property owners.
The stretch is 40 per cent complete.
Infrastructure Principal Secretary Julius Korir said on Tuesday that the main challenge is lack of access by the contractor.
Korir said Sh12 billion is needed to pay for land and structures.
The Sh16.4 billion six-lane highway was to be completed in 36 months after the construction started in August 2017.
"The Treasury made a provision within the budget. We are waiting for NLC commissioners to complete the process," Korir said during a tour of the project accompanied by Kenya National Highways Authority director-general Peter Mundia.
Wu Yi construction company is building the road that ends at the Mai Mahiu turnoff on the Nairobi-Nakuru highway.
The section between Gitaru and ABC has not been done due to non-compensation.
Work has been going on from Gitaru to Rironi after landowners were paid Sh1.2 billion.
Korir said four bridges in Rironi are almost complete.
