Zimbabwean President Robert Mugabe left for a medical check-up in Singapore on Tuesday, his spokesman said, a month before an election in which the 89-year-old is looking to extend his 33 years in power.
Africa's oldest leader - who denies reports he has received treatment for prostate cancer - will return at the weekend after a routine visit to an eye specialist, his spokesman George Charamba said in a statement.
Mugabe has said he has cataracts but no other major health problems and regularly dismisses media allegations that his health is deteriorating as wishful thinking by his enemies.
He has often gone to Singapore for medical check-ups and passed through the southeast Asian city state during a trip to Japan three weeks ago.
Mugabe's main political rival Prime Minister Morgan Tsvangirai has called for a delay of at least two weeks to the vote, currently scheduled for July 31.
Tsvangirai has appealed to the 15-nation Southern African Development Community (SADC) to prod Mugabe into delaying the poll to allow media and security reforms designed to prevent a repeat of the bloodshed that marred a 2008 vote.
Mugabe says the date is in line with a Constitutional Court order and accuses his political rivals of seeking to delay elections because they fear defeat, a charge dismissed by Tsvangirai's Movement for Democratic Change (MDC).
The MDC says reforms to restrictive media and security laws are essential for a credible vote, and accuses Mugabe of using violence to win previous elections.
Besides the quarrel over reforms and the election date, Finance Minister Tendai Biti from Tsvangirai's party also says the southern African state does not yet have the $132 million needed to fund the election.
Mugabe has been in power since independence from Britain in 1980.
His critics accuse him of ruining one of Africa's most promising economies with policies such as the seizure of white-owned farms to resettle landless blacks and forcing foreign-owned firms to sell majority stakes to locals.