In an interview with Aljazeera to be broadcast next Friday, Zenawi cautioned that the existing tensions between the two countries could escalate into a new cycle of violence, unless the two moved to normalise bilateral relations.
Zenawi said he could see no reason why Eritrea could not join the Sanaa Group - formed by Ethiopia, Sudan and Yemen - but insisted that it should first give up attempts to disrupt stability in the region.
Ethiopian authorities, meanwhile, said four people had been arrested in connection with the killings last month of two opposition members before the country's May general elections.
"Four people have been arrested and taken into custody," Kemal Bedri, the chief of Ethiopia's national election commission said.
Ethiopia goes to the polls in May
with 25 million registered voters
The killings, which took place in the northern Gojam region in January, were the most serious violence to be reported since the beginning of the electoral process.
An opposition umbrella group, the Coalition for Unity and Democracy (CUD) has accused the ruling Ethiopia People's Revolutionary Democratic Front (EPRDF) of Prime Minister Zenawi of being behind the killings.
The CUD, which groups three opposition parties, said its supporters had been killed by a pro-government mob in an orgy of destruction that included looting and the torching of huts.
Bedri said the four suspects were indeed allied to the EPRDF and that the murders had occurred during a 19 January clash between supporters of the party and the opposition.
The May elections will mark the third time that Ethiopians will vote directly to elect leaders since Zenawi's EPRDF took power in 1991.
The campaign got under way on 16 February with 77 political parties and 25 million voters registered to take part.