Speaking at an event at the Presidential Secretariat, Rajapakse said Sirisena had informed him of his decision, reports Xinhua news agency.
The move comes after Parliament Speaker Karu Jayasuriya met Sirisena on Wednesday and urged him to convene Parliament to solve the ongoing political crisis which erupted after the President appointed Rajapakse as the Prime Minister following the sacking of Ranil Wickremesinghe from the post last week.
Jayasuriya said he had received the signatures of 125 legislators, urging him to convene parliament to vote as to which party had the majority support.
On October 27, Sirisena prorogued parliament till November 16.
(With inputs from agencies.)