Harare - "As a comrade of our struggle, Comrade Mengistu and his government played a key and commendable role during our struggle for independence and no one can dispute that," William Nhara, a spokesperson for President Robert Mugabe's government, said.
"The judgment is an Ethiopian judgment and will not affect his status in Zimbabwe. As far as we know there is no extradiction treaty between Harare and Addis Ababa."
An Ethiopian court on Tuesday found Mengistu guilty in his absence of genocide for atrocities committed under his Marxist regime, after a 12-year trial.
Mengistu, who was ousted in 1991 and took exile in Zimbabwe, faces the death penalty.
Nhara said Mengistu helped train Zimbabwean guerillas in Ethiopia and provided arms during the war against British colonial rule which culminated in the country's independence in 1980.
"After independence Comrade Mengistu's government provided training for our air force pilots and not many countries have shown such commitment to us."
Nhara said Mengistu was persuaded to leave Addis Ababa following his ouster by the governments of Britain and United States as there were fears of bloodshed if he remained in Ethiopia.
He said Mengistu had initially intended to settle in Kenya but later decided it was too close to Ethiopia.
Zimbabwe's acting information minister Paul Mangwana has said the verdict on Mengistu would not change Zimbabwe's position on the former dictator.
"Comrade Mengistu asked for asylum and he was granted that asylum. That position will not change," Mangwana said on Tuesday.
The charges against Mengistu and his co-accused relate to atrocities committed during the 1977-78 "Red Terror" period when tens of thousands of people were killed or disappeared in his bid to turn Ethiopia into a Soviet-style workers' state.
He and his former top aides were also accused of the murders of Ethiopia's emperor Haile Selassie, who claimed descent from the Queen of Sheba. The emperor was toppled in a 1974 coup.