Storms and floods across six Central American nations have killed at least 34 people affected 333,000, the United Nations said Friday, warning of a rising toll.

Torrential rains that have swept across Honduras, Costa Rica, Belize, Nicaragua, El Salvador and Guatemala in the last week "are the worst that we have seen in many years," said Elisabeth Byrs, spokeswoman for the UN Office for Coordination of Humanitarian Affairs (OCHA).

The crisis was particularly "dramatic in Honduras" where 23 people were killed and 193,000 others affected after widespread landslides, she said. Some 23,000 people have left their homes and 19,000 are in shelters.

Authorities have asked for international aid.

"The losses in the most affected departments are expected to increase considerably," she warned, adding that UN experts have been sent to evaluate needs.

In Costa Rica, the rainfall was the highest recorded in 40 years and seven people had died with 92,000 people affected.

"All main roads located in the northern and southern regions of the country are blocked due to landslides," said Byrs.

In Nicaragua, there were 10,633 people affected and in El Salvador the country remained on alert due to rain, flooding and landslide risks.

Storms in Guatemala have claimed four lives and affected 35,000.