"We are hoping to see a government in place, an operational government in the very, very near future," ambassador James McGee told reporters during a visit to a clinic treating cholera patients in the capital Harare.
After former US secretary of state Condoleezza Rice said late last year it was "well past time" for Mugabe, 84, to step down as leader, the United States now appears to be resigning itself to the prospect of Mugabe presiding over a power-sharing government.
According to the terms of a September accord, Mugabe would remain president and Tsvangirai would become prime minister of a government composed of both their parties.
After holding out for four months for a fairer deal on the way power will be concretely shared between the two parties, the MDC is due to vote on Friday on whether to throw in its lot with Mugabe.
MDC leader Morgan Tsvangirai has tentatively endorsed the move, pending the resolution of some outstanding demands.
McGee’s remarks came as aid agencies again sounded the alarm over the legions of hungry in Zimbabwe. Over half of Zimbabwe’s population of about 11 million require food aid, but appeals for donations by the UN World Food Programme, Oxfam and others NGOs are being increasingly ignored in the West.
The situation is affecting the treatment of cholera patients, more than 3 000 of whom have died since August. The outbreak is a manifestation of the breakdown of state infrastructure as state coffers run on near empty.
"We are taking good medication but I am starving," said one patient who asked to be identified as Spiwe at a clinic in Budiriro township. "I could have been discharged long back but I am here since Monday because I am not eating well."
"Food is the major problem cholera patients are facing all over the country," Oxfam country director in Zimbabwe Peter Mutoredzanwa told reporters.
Handing over a further $365 000 in US government funding for cholera to the UN Children’s Fund USAID, McGee said: "I wish Zimbabwe (government) could do more to help its own people." – Sapa-dpa