"They also pledged more support which will be guided by the way in which we meet our own political commitments," he added.

Deepening crisis
  
During his visit Tsvangirai met heads of state in London, Washington, Berlin, Stockholm, Brussels and Paris to appeal for assistance to rebuild the economy.

Tsvangirai told reporters that he had received pledges totalling almost $500m for humanitarian and transitional assistance, but said the details will follow.

Tsvangirai and Robert Mugabe, the president, formed a power-sharing government a year after disputed elections plunged Zimbabwe deeper into economic and political chaos.

But leaders of the countries the prime minister visited had expressed reservations about the delays in implementing the deal underpinning the unity government.

Tsvangirai has insisted that Mugabe's presence in power should not deter foreign governments from helping his country, but ongoing human rights abuses in Zimbabwe continue to be reported.

Last week Mugabe, who has led Zimbabwe since 1980, criticised the West for refusing to lift sanctions against him and his inner circle until tangible reforms are seen.

The new government is seeking $8.3bn to revive its economy, battered by years of  political turmoil and a deepening economic crisis under Mugabe.