Tanzania's leader Jakaya Kikwete says that condemning Zimbabwean President Robert Mugabe is counterproductive.
Tanzania says pressure on Mugabe is counter-productive
He said calling Mr Mugabe a murderer and a violator of human rights would not resolve the crisis in Zimbabwe.
His comments come ahead of a December summit of European and African leaders which the UK's Gordon Brown says he will not attend if Mr Mugabe goes.
But on a visit to South Africa, the German chancellor said Mr Mugabe should be allowed to attend the summit.
Angela Merkel met with South African President Thabo Mbeki and described the situation in Zimbabwe as "disastrous".
"[It] is a very difficult one. It's a disastrous one, which I very clearly stated in our conversation," the German leader told a press conference.
Ms Merkel had already signalled that she would attend the summit in Lisbon in December come what may.
Speaking in Ethiopia on the first leg of her first-ever sub-Saharan African tour, Ms Merkel said on Thursday that countries of the Southern African Development Community (Sadc) regional bloc should all work together to pressure President Mugabe.
President Mbeki said he was "very confident" that there would be a positive outcome in the talks between the political parties in Zimbabwe, South African Press Association (Sapa) reports.
Zimbabwe has the world's highest inflation rate, and four out of five people there live below the poverty line.
'Price freeze backfires'
"Mugabe is there. He is president; he has been elected," Tanzania's President Kikwete said in an interview with the London-based Financial Times (FT) newspaper.
Mr Kikwete says African diplomacy should resolve the Zimbabwe crisis
"If Tanzania said, 'You are hopeless! A murderer! A violator of basic human rights!' does that remove Mugabe from office? It doesn't."
He said international powers should instead put their weight behind regional diplomatic efforts which "will pay dividends over time".
The Tanzanian viewpoint is that by working with the Zimbabwean leader they hope to get the next year's elections conducted freely and fairly.
According to the FT, Sadc finance ministers have been reviewing how to shore up Zimbabwe's collapsing economy - the official inflation rate is currently 6,500%.
Meanwhile, Zimbabwe's police have revealed that more than 23,000 people have been arrested for flouting price controls imposed by the government three months ago.
"As Operation Reduce Prices continues, we have so far as police arrested 23,585 people," Sapa quotes police spokesperson Oliver Mandipaka as telling state radio.
The crackdown has backfired and there are now chronic shortages of basic foodstuffs on the formal market, Sapa reports.