A slew of tropical storms and monsoon rains has pummelled Southeast and South Asia, triggering landslides and flash floods from the rainforests of Indonesia's western Sumatra island to the highland plantations of Sri Lanka.

"Everything is lacking, especially medical personnel. We are short on doctors," Muzakir Manaf, governor of Indonesia's Aceh province, told reporters late Sunday.

"Basic necessities are also important. It's not just one or two items."

Indonesia's national disaster mitigation agency (BNPB) said 950 people in Aceh, North Sumatra and West Sumatra had been killed, while 274 were missing.

The downpours and subsequent landslides injured at least 5,000 people and devastated infrastructure.

Hospitals, schools and offices are in ruins, while many bridges have been destroyed, cutting off communities.

Costs to rebuild after the disaster could run up to 51.82 trillion rupiah ($3.1 billion), the BNPB said late Sunday.

- Extra troops -

In Sri lanka, the military deployed thousands of extra troops to aid recovery efforts there after a devastating cyclone cut a swathe of destruction killing 627 people

More than two million people -- nearly 10 percent of the population -- have been affected by Cyclone Ditwah, the worst on the island this century.

Sri Lanka is expecting further heavy monsoon rains on Monday, topping five centimetres in many places, the Disaster Management Centre (DMC) said. It issued warnings of further landslides.

Army chief Lasantha Rodrigo said 38,500 security personnel had been deployed to boost recovery and clean-up operations in flood-affected and landslide-hit areas, nearly doubling the initial deployment.

"Since the disaster, security forces have been able to rescue 31,116 people who were in distress," Rodrigo said in a statement.

President Anura Kumara Dissanayake unveiled a recovery package, offering 10 million rupees ($33,000) for victims to buy land in safer areas and rebuild.

There is also livelihood support and cash assistance to replace kitchen utensils and bedding and to buy food.

It is not clear how much the relief package will cost the government, which is still emerging from economic meltdown in 2022 when it ran out of foreign exchange to finance even the most essential imports.

Dissanayake has said the government cannot fund reconstruction alone and has appealed for foreign assistance, including from the International Monetary Fund.

In Indonesia's Banda Aceh, long queues formed for drinking water and fuel, and prices of basic commodities such as eggs were skyrocketing, an AFP correspondent said.

Seasonal monsoon rains are a feature of life in South Asia and Southeast Asia, flooding rice fields and nourishing the growth of other key crops.

However, climate change is making the phenomenon more erratic, unpredictable, and deadly throughout the regions.