The armed forces of the Central American country have intervened in politics in the past and carried out several coups d'etat, most recently in 2009 when they ousted then-president Manuel Zelaya -- husband of incumbent leftist leader Xiomara Castro.

"We have been clear," armed forces chief Roosevelt Hernandez insisted Wednesday. "We have said we will support and recognize the results" that emerge from the count underway by the CNE electoral council, with two right-wingers neck-and-neck.

Hernandez, who is close to the outgoing government, told Televicentro that the military would "ensure... the transfer of the presidency of the republic."

Right-wing businessman Nasry Asfura, backed by US President Donald Trump, has a razor-thin lead in the count over TV personality Salvador Nasralla.

Suspicions of interference have been fueled by successive computer failures that have stalled tallying, which the CNE legally has a month to complete.

Nasralla has claimed fraud in the process, backed by outgoing Castro and the trailing leftist candidate Rixi Moncada, who has called for an election annulment.