"I prefer active politics to a life of retirement," the Daily Financial Times quoted the President as saying on Twitter on Monday evening.
Sirisena's term will end in January 2020.
This was the clearest indication that Sirisena has planned to enter Parliament through the National List at the end of his term as has been speculated for days.
Meanwhile, an agreement between the Sri Lanka Podujana Peramuna's (SLPP), headed by former President Mahinda Rajapaksa, and the Sirisena-led Sri Lanka Freedom Party (SLFP), to form an alliance called the Sri Lanka Nidahas Podujana Sandanaya will be signed on Thursday.
Sirisena and Rajapaksa will be named co-leaders of the party.
A record 35 candidates have filed their nominations for the island nation's eighth presidential election.
Of the 35 hopefuls, SLPP's Gotabaya Rajapaksa and the ruling United National Party's (UNP) Deputy Leader Sajith Premadasa, who is contesting as the National Democratic Front (NDF) contender, have emerged as the two favourites.
Gotabaya Rajapaksa, who served as the Defence Minister in his brother Mahinda Rajapaksa's administration, oversaw the end of Sri Lanka's brutal 25-year civil war in 2009.
Premadasa is the son of late President Ranasinghe Premadasa, who ruled the country with an iron fist before he was assassinated by a Tamil suicide bomber on May 1, 1993.
( With inputs from IANS )