The US Bureau of South and Central Asian Affairs, an agency within the State Department, stated on Twitter: "The US is deeply concerned by news the Sri Lanka Parliament will be dissolved, further deepening the political crisis".
The dissolution is the latest twist in a constitutional crisis that began October 26 when Sirisena unexpectedly fired Ranil Wickremesinghe, who served since 2015 as prime minister in a unity government with Sirisena.
Following the Parliament's dissolution on Friday, the United National Party - of which Ranil Wickremesinghe is the leader - vehemently rejected the move, and said that it was illegal. His request for a floor test to prove his majority in the House has been turned down. Sirisena said he had to fire Wickremesinghe for mismanaging the economy and because of a Cabinet minister's alleged involvement in a plot to assassinate Sirisena.
Sirisena was hoping to get Rajapaksas support for a second term in Presidency.
"Now we have a caretaker government with limited functions", Premajayantha said. It said the names of candidates will be called before November 26, and the election held on January 5.
"It was a follow-up action to the executive's earlier actions - removing the prime minister, appointing a new prime minister and proroguing parliament".
Keheliya Rambukwella, a spokesman for Sirisena's government, said the president's coalition had the backing of 105 lawmakers as of Friday, eight short of a parliamentary majority.
Mr Wickremesinghe's camp is likely to contest Mr Sirisena's move because of constitutional provisions stating a parliament can't be dissolved until four and a half years after it is elected. The dissolution came hours after a close aide of the president said that Sirisena had decided that there will be no snap election or a national referendum to end the political turmoil.
The leftist People's Liberation Front (JVP), which regards the sacking of Wickremesinghe as unconstitutional, accused Sirisena of trying to consolidate his power grab.
The TNA will seek an interim order suspending the President's proclamation on the dissolution of Parliament and calling for general election, party sources said.
The EU said on Friday, before the dissolution, that the crisis had scarred the Indian Ocean island's global reputation.
The EU, in a joint statement with Norway and Switzerland, called for parliament to reconvene and hold an immediate vote. Rajapaksa also backed the president, tweeting that "it is our responsibility and obligation to give the people the opportunity to voice their opinions on the future of #SriLanka".
"You have not let this country be plunged into the darkness of dictatorship". It said democracy needed to be respected to ensure stability and prosperity.
The power struggle on the island of 21 million people has paralysed much of the administration, according to legislators on both sides of the dispute.