Sri Lanka's Parliament Speaker Mahinda Yapa Abeywardena on Wednesday said President Gotabaya Rajapaksa has informed him over telephone that he will resign today as promised.

Rajapaksa, 73, fled to the Maldives in the morning before he was due to officially resign after months of protests against his government's economic mismanagement that has led to severe shortages of food, fuel and other essentials in the country.

Speaker Abeywardena said President Rajapaksa has telephoned him to confirm that he would be sending his resignation today as pledged.

He said the vote for the new president will take place on July 20 and urged citizens to remain calm.

On Saturday, Rajapaksa had announced to step down on Wednesday after thousands of protesters stormed his official residence, blaming him for the unprecedented economic crisis that has brought the country to its knees.

Sri Lanka, a country of 22 million people, is under the grip of an unprecedented economic turmoil, the worst in seven decades, leaving millions struggling to buy food, medicine, fuel and other essentials.