As of 7 pm local time on Sunday, Iota was 410 km off the Nicaraguan-Honduran coast, packing maximum sustained winds of 160 km/h, according to the US National Hurricane Center.

Iota "is expected to bring potentially catastrophic winds, a life-threatening storm surge and extreme rainfall impacts to Central America," the NHC said.

Authorities are warning the hurricane could exacerbate the massive destruction wrought by Eta, which slammed into the region two weeks ago, causing flooding and mudslides that destroyed crops and killed scores of people across a huge swath from Panama to southern Mexico.

The unprecedented 2020 hurricane season comes with Central America facing economic crisis linked to the coronavirus pandemic, with experts warning compounding hardship could fuel further migration from the region.

"Increased movements across borders are now more likely, including of people fleeing violence and persecution," Central America and Cuba representative for the United Nations Refugee Agency Giovanni Bassu said on Friday.

The UNHCR said climate change is increasing the intensity of rain and drought across Central America which could exacerbate conditions that "continue to drive people to flee their communities".

Last week, Guatemala requested the United States allow its nationals in the US to remain on humanitarian grounds following Eta, under a provision known as temporary protected status, or TPS.

Evacuations are already under way in Honduras, Guatemala and Nicaragua in areas expected to be affected by Iota, which is slated to smash into the jungles of the Mosquito Coast of Nicaragua and Honduras on Monday.

In Honduras, Douglas Espinal, head of the fire department of Puerto Lempira on the Mosquito Coast, said evacuees have been arriving since early Saturday from the region's remote peninsulas.

"People are coming from the coastal areas but only those who have a boat or a canoe. The rest are staying in their communities," he said.

Australian Associated Press