The African Union's executive council adopted a resolution ahead of of Sunday's summit in Addis Ababa calling for "the lifting of sanctions against Zimbabwe to help ease the humanitarian situation in the country."
African Union head Jean Ping, when asked about sanctions levied by the United States and European Union, said: "I think that everybody today should help Zimbabwe to rebuild its economy, because an agreement has been reached.
Since disputed elections in March 2008, Zimbabwe's shattered economy has further plummeted. It has the world's highest inflation rate -- 231 million per cent -- and is struggling with a cholera epidemic that has claimed some 3,000 lives.
Zimbabwe's opposition leader Morgan Tsvangirai Friday acceded to a decision by the Southern African Development Community regional bloc that a unity government be formed under a strict timeline which would see him sworn in as prime minister on February 11.
The 53-nation AU asked members and partners "to solidly back the implementation of a comprehensive pact" to end the ruinous political and economic stalemate.
Mugabe's party, which had previously threatened to set up a unity government with or without Tsvangirai, has said it will accept the timetable.
The 84-year-old president -- in power since Zimbabwe's independence from Britain in 1980 -- has long accused Tsvangirai's Movement for Democratic Change party of being a tool of Britain and the United States, whose governments are opposed to his regime.
Pretoria on Saturday said Western nations should take steps to help its stricken northern neighbour rebuild.
"Now that (Morgan Tsvangirai) has decided to be part of the inclusive government... it requires them to call for the end of sanctions," said Frank Chikane, director general in the South African president's office.
"So we expect Europe and the US and other countries to stop the sanctions," he told South African public radio station SAfm.
Elder statesmen including former UN chief Kofi Annan and US ex-president Jimmy Carter meanwhile called for international donors to support Zimbabwe and give the power-sharing pact a chance to work.
"This political agreement is far from perfect -- but political life involves taking risks. Talking it down will not improve the situation for Zimbabweans -- it will only prolong their agony," said Carter.
"This is an important step towards ending the political impasse in Zimbabwe," said Annan, "but it is not a guarantee that Zimbabwe's distress is over."
South African Archbishop Desmond Tutu said the people of Zimbabwe could "no longer be held hostage by politics. Their urgent needs must be met."
But London and Washington offered up restrained hope in response to the announcement of a unity government, saying such announcements had been made before and stressing that implementation of pacts were vital.
EU foreign ministers had on Monday tightened sanctions on Zimbabwe, freezing the assets of companies based in British tax havens for the first time and adding 26 more names of people close to the Mugabe regime or their families to a travel-ban list, bringing the number to 203.
The amount of companies whose assets in Europe must be frozen was increased sharply from four to 40 and for the first time European-based firms are included.
According to EU sources, all 18 of the European company names added are based on British territory, including tax havens Jersey, the Isle of Man and the British Virgin Islands.