The presidents of Ghana, Nigeria and Senegal are due to arrive in Burkina Faso to press the military for a speedy handover of power to a civilian ruler.
The African Union (AU) says the army acted unconstitutionally when it took over after President Blaise Compaore was forced to resign last Friday.
The AU on Monday gave the army a two-week deadline. Interim leader Lt Col Isaac Zida later promised to comply.
Mr Compaore quit after mass protests at his bid to extend his 27-year rule.
‘No reason’
Senegalese President Macky Sall, Goodluck Jonathan of Nigeria and Ghana’s John Mahama are expected to arrive in the capital Ouagadougou later on Wednesday.
They will hold a series of meetings to press for the quick handover, following a threat by the AU to impose sanctions if the military did not act within two weeks.
After meetings with opposition leaders and activists, Lt Col Zida was on Tuesday quoted as saying that he would comply with the demand.
“If everyone agrees, there is no reason that the transition shouldn’t be done within two weeks,” he said, according to union leader Joseph Tiendrebeogo, the AFP news agency reports.
Opposition leaders have not entirely ruled out a role for the military in the transition.
Lt Col Zida was previously second in command of the presidential guard.
Amid the protests, Mr Compaore fled to neighbouring Ivory Coast and is currently staying in the capital Yamoussoukro.
France – the former colonial power – has admitted helping in the evacuation of Mr Compaore.
The streets of Ouagadougou were reported calm on Tuesday.
The AU warned it would apply sanctions against Burkina Faso if its handover deadline was not met.
The BBC’s Emmanuel Igunza in the Ethiopian capital Addis Ababa says the sanctions could include suspension of Burkina Faso’s AU membership and a travel ban on military officials.
The AU’s Peace and Security Council is expected to meet again later this month to discuss the crisis, he says.
Under Burkina Faso’s constitution, the head of the National Assembly should take office if the president resigns.
Mr Compaore first seized power in a coup in 1987, and thereafter won four disputed elections.
The protests were triggered by his plan to amend the constitution so that he could run for office again in elections next year.