The health ministry in Nicaragua says it has quarantined a member of staff at the US embassy in Managua amid concerns over contact with Ebola.
Nicaragua has asked the US to send a plane to remove him.
The embassy acknowledged the man had travelled to Liberia but he had not come into contact with Ebola patients.
It said he had no sign of haemorrhagic fever and that both the US and Nicaragua's health ministry had cleared him to return.
The embassy said the 51-year-old man had been examined at the Center for Disease Control and Prevention in the US before returning to Nicaragua.
However, the Nicaraguan government has asked the US state department to send a plane "with all the equipment necessary" to take him back to the US.
The health ministry has isolated him at his home, setting up a security corridor around it.
"The man confirmed that he had spent time in health facilities where Ebola patients are being treated," said the head of epidemiology at the health ministry, Carlos Saenz.
"The man does not show any symptoms of the disease and the measures are strictly preventive," he said.
A number of Latin American countries have banned travellers from Ebola-stricken countries in West Africa.
The Ebola outbreak in West Africa that erupted last year has killed more than 10,000 people, almost all of them in Liberia, Guinea and Sierra Leone.
But the World Health Organisation says the number of new cases has fallen and the risk of the disease spreading appears to be receding.