US President Barack Obama called Saturday for Zimbabwe's government to stop harassing its citizens and to implement reforms ahead of landmark elections expected later this year.
"Harassment of citizens and groups needs to stop and reform needs to move forward so people can cast their votes in elections that are fair and free and credible," he said during a visit to neighbouring South Africa.
Veteran president Robert Mugabe has set elections for July 31, drawing fierce criticism from his political foes.
Critics accuse Mugabe of attempting to push through a vote before reforms that would clean up the electoral roll, free the media and limit the military's political role.
Prime Minister Morgan Tsvangirai -- who will face Mugabe in the polls -- has threatened to boycott any unilaterally declared election date.
Tsvangirai won the most ballots in the first round of the 2008 elections, but pulled out of the second round amid violence against his supporters.