US President Donald Trump has signed into law a bill that imposes tough new conditions that have to be met before sanctions are lifted.
President Emmerson Mnangagwa has said that his country is open for business, but this new law - the Zimbabwe Democracy and Economic Recovery Amendment Act - could scupper those plans as far as the US is concerned.
Official results show that Mr Mnangagwa won last month's presidential election with 50.8% of the vote, but the opposition alleges that the figures were manipulated.
The US law says that in order for sanctions to end the election has to be "widely accepted as free and fair".
One condition mentioned is that the army has to "respect the fundamental rights and freedoms of all persons and to be nonpartisan in character".
In the days following the poll, six opposition supporters died in clashes with the army, which has led some to question its neutrality.
Zimbabwe is also required to take steps towards "good governance, including respect for the opposition".
In recent days, the US has criticised the treatment of opposition supporters and in particular key opposition figure Tendai Biti, who has been arrested in connection with the post-election violence.
"The United States government is gravely concerned by credible reports of numerous detentions, beatings, and other abuses of Zimbabweans over the past week, particularly targeting opposition activists", State Department spokesperson Heather Nauert said.
"We call on Zimbabwe’s leaders to guarantee Mr Biti’s physical safety and ensure his constitutional and human rights are respected."
The US started imposing sanctions on Zimbabwe in 2001. They target individuals, as well as banning trade in defence items and direct government assistance for non-humanitarian programmes.