British Prime Minister Gordon Brown has pledged an extra $US8 million in aid for Zimbabwe, after talks with his counterpart Morgan Tsvangirai.
The BBC reports this takes the total this year to $US98 million but Mr Brown said more money would only come after further reform.
He also said the aid would go through aid agencies, not the government in which Mr Tsvangirai shares power with President Robert Mugabe.
Zimbabwe says it needs $US8 billion to revive its economy.
Mr Tsvangirai has been on a tour of Europe and the United States to ask for increased funding but many donors are still wary of sending money which could be misused by Mr Mugabe and his allies.
At a news conference in London, Mr Tsvangirai said "irreversible change was now taking place in Zimbabwe towards a transition to democracy and elections".
However, he was booed on Saturday in London by Zimbabwean exiles when he urged them to return to the country.
Mr Tsvangirai is due to return home on Wednesday.