Abiy’s remark comes hours before the expiry of a three-day surrender ultimatum he had given to the rebels in the northern region of Tigray.
Late Sunday, the premier gave the Tigray People's Liberation Front (TPLF) 72 hours to surrender or face an offensive. The rebels dismissed the ultimatum.
Abiy, a Nobel Peace Prize laureate, has resisted calls by the United Nations, the African Union, and various countries for talks with the armed rebels.
He said in a statement on Wednesday that Ethiopia appreciated the concern but emphasized that his government was "very much capable" of resolving the issue on its own.
“While we consider the concerns and advice of our friends, we reject any interference in our internal affairs.”
“We therefore respectfully urge the international community to refrain from any unwelcome and unlawful acts of interference and respect the fundamental principles of non-intervention under international law,” the prime minister added.
Ethiopian forces are reportedly encircling Mekele with tanks and preparing for the assault, and have called on the city’s half a million residents to leave.
Rights groups have warned that attacking Tigray's capital could constitute a war crime.