A cyclone that made landfall in Sri Lanka last week triggered heavy rainfall, floods and landslides that the United Nations described Monday as among the worst recent flooding in the country's history.

Spokesperson Stefan cited government reports of 366 people killed, 367 missing and more than 1.1 million people impacted across 25 districts. More than 215,000 people are sheltering in over 1,500 government-run safety centres, he said, and initial assessments report more than 15,000 homes destroyed and extensive damage to infrastructure including rail and power systems.

"The UN in Sri Lanka is rapidly mobilizing to provide immediate and life-saving support, including food, safe drinking water, hygiene, shelter items, as well as maternity and dignity kits," Stefan said. He added that the UN is coordinating joint needs assessments with national authorities and preparing a joint response plan supported by OCHA's regional office for the Pacific.

Stefan said the UN country team has been activated and emphasized the need for donor support to fill funding shortfalls and reach people in greatest need.

The briefing did not include a figure for the UN's requested appeal total; Stefan said more detailed assessments and notes would be circulated to reporters.