Mr. Mugabe described the farm invasions as "a problem," but said that only his government could correct it.
In the late 1990s and early 2000s, Shiri was reported to have organised farm invasions by war veterans.
Meanwhile, five more farm invasions were reported overnight.
But he said the black war veterans leading the farm invasions would not leave until a start had been made on redistributing land.
In an incident that appeared to be unrelated to the farm invasions, a 76-year-old white farmer was killed by assailants at his home.
And last year his association of former freedom fighters led farm invasions and violent attacks on opposition supporters with the government's backing.
More than 600 companies have closed over the past year and farm invasions and political violence have sharply reduced foreign investment.
The move was seen as a message that the government would not tolerate the kind of farm invasions that have occurred in Zimbabwe.
But they say the farm invasions have also played a role.
His supporters threatened to kill the Supreme Court justices who deemed the farm invasions illegal.