On Wednesday U.S. Ambassador James McGee articulated more specific criteria by which Washington will measure the success of the agreement, calling for a “ratcheting up” towards adherence to key principles including the restoration of the rule of law, respect for human rights, a crackdown on corruption, and the restoration of a market economy.

McGee told reporter Blessing Zulu of VOA's Studio 7 for Zimbabwe that he is "cautiously optimistic," but that all parties to the deal must implement in good faith.

If the new unity government can show that it is moving to meet the principles set out by the United States, "we will be very, very pleased with this arrangement," he said.

Asked what it would take for Washington to lift its sanctions targeting President Robert Mugabe's inner circle, McGee said this would be "performance-based."

"Our reengagement with Zimbabwe will be based upon the performance of this government. And if this government is moving in a positive direction, then our response will be a very positive one," he said. But, if the government "continues along the same path as previously our response will be...likewise in that same direction."

As to ramping up food assistance to an increasingly hungry population, McGee said that although the power-sharing agreement does not assert the right of NGOs to deliver aid, the U.S. is telling its partners to "get out there in the field and do their job."

McGee added that, "We don't expect to have any issues from anyone in this country," noting that prime minister designate Morgan Tsvangirai has told him that "he himself will be out in the field next week seeing to the food insecurity problems."

On the economy, McGee said market mechanisms must be restored - and strong action must be taken to break the hyperinflationary cycle that has taken hold.

"First of all the uncontrolled printing of money has to be stopped. The central bank has to be reined in." Zimbabwe must restore the rule of law so companies don't have to fear confiscation and can make "fair profit" to recoup costs. Above all the government must reassure people "that there is a true turnaround happening in this country."

More reports from VOA's Studio 7 for Zimbabwe...