“We have the first flight of the agreement financed by the US,” Panamanian vice-minister of security Luis Felipe Icaza, accompanied by US officials, told reporters after the charter flight took off at dawn en route to Bogota.

Before boarding the Fokker 50 aircraft, the group was lined up on the side of the runway and each was screened with metal detectors.

The 29 deportees, who had no luggage, were handcuffed and climbed the plane’s stairs slowly.

Icaza said the next flight could depart on Friday or Saturday under the deal that Panama signed with the US in July.

Washington pledged US$6 million in funding for migrant repatriations from the Central American nation in the hope of reducing irregular crossings at its own southern border.

In a first phase, migrants with a criminal record will be deported, but the agreement could see the deportation of any person entering Panama through the notoriously dangerous and rugged Darien Gap region on their way to the US.

This was the first group of migrants deported under the agreement, although Panama sent several charter flights earlier this year to Colombia with Colombian nationals with criminal records.

The Darien Gap between Colombia and Panama has become a key corridor for migrants travelling overland from South America through Central America and Mexico to the US.

Despite the dangers, including attacks by criminal gangs, more than half a million undocumented migrants – mostly Venezuelans – crossed the Darien last year.

Transit countries such as Panama and Mexico have come under increased pressure from Washington to tackle the highly contentious migration issue in a US election year.