The cyclone killed more than 640 people when it swept across the South Asian island last month, causing floods and landslides that inflicted about $4 billion in damage, according to the World Bank, or 4 per cent of the country's GDP.

Sri Lankan President Anura Kumara Dissanayake has described the storm, which affected more than two million people, as the most challenging natural disaster in the island's history.

Jaishankar, who is on a two-day visit, told a media briefing in Colombo he had handed a letter from Prime Minister Narendra Modi to Dissanayake, committing to a "reconstruction package of $450 million".

While $350 million will take the form of "concessional lines of credit", the remaining $100 million will be given as grants.

Jaishankar also noted the 1,100 tons of relief material, along with medicine and other necessary equipment, sent to India's southern neighbour in the cyclone's immediate aftermath.

"Given the scale of damage, restoring connectivity was clearly an immediate priority," he said, detailing the Indian military's assistance in providing portable bridges.

Jaishankar said India would also look at other ways to mitigate the losses, including encouraging Indian tourism to Sri Lanka.

"Similarly, an increase in foreign direct investment from India can boost your economy at a critical time," he added.

The cyclone struck as Sri Lanka was emerging from its worst-ever economic meltdown in 2022, when it ran out of foreign exchange reserves to pay for essential imports such as food, fuel and medicines.

Following a $2.9 billion bailout from the International Monetary Fund approved in early 2023, the country's economy has stabilised.