Johnnie Carson, the assistant secretary of state for Africa, said Zimbabwe has made "important progress," particularly in reviving a crippled economy, since President Robert Mugabe entered a power-sharing deal in February.
Under the so-called Global Political Agreement (GPA), Zimbabwe is supposed to draft a new constitution by August next year followed by free elections in a nation led by Mugabe for nearly 30 years.
"The international community has joined us in calling for transparency in the process of drafting a new constitution and the conduct of closely monitored elections," Carson testified before the Senate Foreign Relations Committee.
"We also call on the nations of Africa, in particular the members of the Southern African Development Community, to ensure that Mugabe and his cohorts fully implement the GPA and work toward democratic reform," he said.
Carson said the United States was "pleased" that Zuma visited Zimbabwe in August and "stressed the importance his government places on democracy and respect for human rights in Zimbabwe and compliance with the GPA."
Western nations had uneasy ties with South Africa’s former president Thabo Mbeki in part due to his insistence on engaging Zimbabwe rather than punishing Mugabe for purported abuses.
Secretary of State Hillary Clinton in August hailed a new relationship with South Africa after she visited and met with Zuma.