The government is set to evict all the people who have invaded Kenya's 18 gazetted water towers.
Environment Cabinet Secretary Keriako Tobiko on Saturday told the encroachers to start preparing to leave.
Speaking at Rubora village in Kirinyaga County during a tree-planting day, Mr Tobiko noted that the illegal settlers will be flushed out regardless of their political affiliations.
"I'm putting the settlers on notice; they must come out of the forests whether they like or not," he said.
While stressing the government's commitment to ending forest destruction, Mr Tobiko said the goal for 10 percent cover by 2022 was on course.
"The presidential order must be implemented so illegal settlers must go. We want to plant two billion tree seedlings to meet our target," he said.
He added, "We have kicked all illegal settlers out of the Mau and are now moving to the other forests. We shall not allow some individuals to mess up forests at the expense of majority of Kenyans."
The minister further told Rift Valley members of Parliament to stop politicising the eviction exercise.
"Some lawmakers are claiming that their communities are being targeted. This is not true. People from various communities have been affected so MPs should stop meddling."
Mr Tobiko praised Kirinyaga's leaders and residents for active involvement in forest conservation.
The region's forest cover currently stands at 20 percent.
The CS promised Green Space, a community organisation that has been helping to conserve Mt Kenya Forest on the Kirinyaga side, 300,000 tree seedlings.