Squatters who have encroached on the Kenya Agriculture and Livestock Research Organisation (Kalro) Kiboko station have been put on notice.
Makueni county commissioner Mohammed Maalim urged the squatters to relocate before they are ejected to allow the research station to fence off its land.
The squatters are more than 200 households.
"Those who have encroached on the Kalro land should start relocating," Maalim said on Tuesday. He spoke at a hotel in Kiboko after meeting county security chiefs and Kalro officials.
Maalim said they will, however, conduct public participation and all players will be consulted before the squatters are moved.
The Sh120 million fencing project is sponsored by David Sheldrick Wildlife Trust.
He urged local leaders to support the fencing project, which is expected to take six months.
The 60km fence is also expected to prevent human-wildlife conflict in the area which borders Chyullu Hills National Park.
Farmers are owed more than Sh400 million in uncompensated claims by the Kenya Wildlife Service, Makueni County Wildlife Conservation and Compensation Committee chairman Nichodemus Kivindyo said.
"The fence will greatly help the station to produce enough fodder seeds to support beef and dairy industries in the country. Stray livestock have frustrated the realisation of this goal," head of the Kalro Kiboko station Simon Mburu said.
Kalro surrendered 25,925 acres of its 71,000-acre rangeland to squatters who were ejected from Chyullu Hills National Park in the late 1980s, following pressure from local leaders.
The remaining squatters claim they were short-changed by powerful government officials during the allocation of the land.
