Deposed president Keita was hospitalised in the capital Bamako, six days after he was released from detention by the ruling junta, which seized power on August 18.
Ousted Mali President Ibrahim Boubacar Keita has left the country for medical treatment in Abu Dhabi as talks about a transition back to civilian rule following last month's military coup got off to a chaotic start.
Keita, 75, was hospitalised in the capital Bamako on Tuesday, six days after he was released from detention by the ruling junta, which seized power on August 18.
His former chief of staff, Mamadou Camara, told Reuters that Keita left Bamako on Saturday evening aboard a plane chartered by the United Arab Emirates at the request of Mali's ruling junta.
"It is a medical visit of between 10 and 15 days," Camara said.
Keita's medical condition is unclear. He had a benign tumour removed from his neck in 2016.
Transition talks begin
Mali's military junta has started talks with opposition groups on its promised transition to civilian rule after mounting pressure from neighbours to yield power in the weeks since it overthrew the nation's leader.
The talks in Bamako are being held under junta chief Assimi Goita but he was not present on Saturday, a military source said.
The West African country has long been plagued by chronic instability, a simmering militant revolt, ethnic violence and endemic corruption, prompting a clique of rebel colonels to detain Keita last month.
They pledged to step down after an undefined transition period, but the putsch has prompted Mali's neighbours and former colonial ruler France to demand a swift transfer of power to civilian rule, with fears the crisis could impact neighbouring states.
"Since August 18, we are charting a new history for our country," junta number two Malick Diaw told the opening session.
The 15-nation Economic Community of West African States regional bloc has imposed sanctions and closed borders to Mali as part of efforts to press the junta into handing over power quickly.
The opposition coalition of civil and religious leaders has demanded that the military rulers give it a role in the transition to civilian rule, but was not invited for the transition talks last Saturday.
It was then included for the rescheduled talks on Saturday and Sunday, along with political parties, former rebels, unions, civil society organisations and media representatives.
Parallel talks will take place in regional capitals, led by regional governors, according to the junta.
Members of the Malian diaspora will also have their say, according to a spokesperson for the National Committee for the Salvation of the People, as the junta is known.
One of the key issues will be the length of the transition to civilian rule.
Originally the junta proposed a three-year transition, before bringing that down to two years.
The June 5 Movement has said it wants a transition period of 18-24 months.
West African leaders, who have called for elections within 12 months, will meet via videoconference on Monday with the Mali situation at the top of their agenda.
No blank cheque
The June 5 Movement led the protests against Keita for weeks before he was removed from power after seven years in charge.
It fears the junta is hijacking the coup and is demanding equal billing during the transition period.
Influential imam Mahmoud Dicko, a key player in the mass opposition protests that led to Keita's ouster, has insisted that the junta does not have "carte blanche".
"We will not give a blank cheque to anyone to run this country, that's over," he said.
READ MORE: Mali's president resigns after military coup
"We led the fight. People have died and the soldiers who have completed (this fight) must keep their word."
Mali's security situation deteriorated in the lead-up to the country's fourth coup since it became an independent nation 60 years ago.
The ill-equipped army has the Herculean task of securing an area two-and-a-half times the size of France from different groups allied to Al Qaeda or Daesh and various militia groups, some fighting for the government and others against it.
At least 10 Malian soldiers were killed in an overnight ambush in a central region near the Mauritanian border where armed militant groups are rampant, security and local sources said on Friday.
It was the third time Malian security forces have suffered heavy losses since the military took power.