"We have not yet seen sufficient evidence from the government of Zimbabwe that they are firmly and irrevocably on a path to inclusive and effective governance, and as well as respect for human rights and the rule of law," State Department Robert Wood told reporters.
"So that government has a long way to go before we will consider … easing sanctions with that government," Wood said.
"We’re not in any kind of discussion with … the government of Zimbabwe on removing our targeted sanctions," he added.
"We remain very concerned about the plight of the Zimbabwean people who have been under such terrible suffering. And we’re going to continue to try to help the people of Zimbabwe," he said.
"With regard to the government, it’s got a long way to go before we will look at removing any targeted sanctions," according to the US spokesperson.
In Harare, Mugabe called for foreign aid to revive his nation’s shattered economy and urged Washington and Brussels to end "cruel" sanctions on his inner circle.
Mugabe issued the appeal at the launch of a new economic recovery plan prepared by the month-old unity government.
The European Union and the United States maintain a travel ban and asset freeze on Mugabe and his inner circle in protest at controversial elections and alleged human rights abuses by his government.
Although his long-time rival Morgan Tsvangirai became prime minister in a unity government last month, western countries say they will maintain the sanctions until the 85-year-old leader proves he is ready to reform.
Zimbabwe’s once-dynamic economy has been crushed by world-record hyperinflation and the collapse of farming, mining and manufacturing.