Zelaya was to be accompanied by Miguel D'Escoto Brockmann, the president of the UN General Assembly.
A second aircraft carrying Cristina Fernandez, Rafael Correa and Fernando Lugo, the presidents of Argentina, Ecuador and Paraguay respectively, was due to fly to nearby El Salvador to monitor Zelaya's return.
"The time is running out for this interim government and not because of international pressure, but because of the Honduran people's pressure," Correa said in Washington.
Al Jazeera's Mariana Sanchez, reporting from Tegucigalpa, said that security was high around the airport in the capital.
"The perimeter of the airport is still closed with troops and police," she said. "Some protesters, Zelaya supporters, are near the airport, but, so far, it seems to be very calm."
More supporters were reported to be marching towards the airport after Zelaya reiterated his intention to return home.
"We have no pistols or arms, just our principles," Rafael Alegria, one of the protest organisers, said. "We have the legitimate right to fight for the defence of democracy and to restore President Zelaya."
The interim government has vowed to arrest Zelaya for 18 alleged criminal acts including treason and failing to implement more than 80 laws approved by congress since taking office in 2006.
Colin Harding, a Latin America analyst in London, said Zelaya was "hoping to force a showdown" by returning to Honduras.
"I think he wants to provoke the interim regime in Honduras into trying to arrest him. I think there is a certain sort of martyrdom attitude in the air," he told Al Jazeera.
"It's possible that we've got brinkmanship here, which will lead to some sort of compromise, which may conceivably allow Zelaya to return at a later date, to bring forward the election date to save the face of both sides."
Oscar Andres Rodriguez, the highest ranking Catholic Church official in Honduras, had earlier urged Zelaya not to come back.
"We think that a return to the country at this time could unleash a bloodbath in the country," Rodgriguez said on national television.
"To this day, no Honduran has died. Please meditate because afterwards it would be too late."
The president was removed from power as he was about to press ahead with a non-binding referendum that his domestic critics said was aimed at changing the constitution to enable him to run again for office.
The Organisation of American States (OAS), a hemispheric bloc dedicated to strengthening political co-operation and reforms, has suspended Honduras's membership over the coup.
"The suspension takes effect immediately," Jorge Taiana, the Argentine foreign minister, said on Saturday.
The move temporarily sidelines Honduras from any participation in the OAS, but obliges it to continue observing the body's rules in areas such as human rights.