Ukraine's new President Volodymyr Zelenskiy took the oath of office on Monday and immediately announced he was dissolving parliament and calling a snap election, aiming to win seats in a legislature still dominated by loyalists of his predecessor.

"I dissolve the Verkhovna Rada of the eighth convocation," the newly sworn-in president said during the ceremony in parliament in Kiev.

Disbanding the Supreme Rada was one of his campaign promises, for Zelenskiy had branded the body as a group of people only interested in self-enrichment.

Before he made the announcement, Zelenskiy asked the parliament to adopt a bill against illegal enrichment and support his motion to fire the country's defense minister, the head of the Ukrainian Security Service and the Prosecutor General. All of them are allies of former President Petro Poroshenko, who lost the presidential election in a landslide to the comedian who had no previous political experience.

In a feisty speech after his inauguration, Zelenskiy told the Rada that his main goal for the presidency is to bring peace to eastern Ukraine, where government troops have been fighting Russia-backed separatists for five years.

Working with parliament will be crucial to his ability to meet the expectations of his voters and also pass reforms needed to keep foreign aid flowing. Elections to the Supreme Rada were scheduled for Oct. 27, which raised the prospect of Zelenskiy struggling to enact his agenda in the face of a hostile parliament over his first few months in power.

Zelenskiy called on lawmakers to use the two months until the snap election to pass a law that would strip them of immunity from prosecution and another law that bans officials from illegally enriching themselves.

"You will have two months for this. Do it and you will deserve medals," Zelenskiy said after being sworn in.

Turkey's Vice President Fuat Oktay was among dignitaries who attended the inauguration ceremony on Monday.

Prime Minister Volodymyr Groysman said he would step down after the next government meeting on Wednesday and that he would take part in the upcoming parliamentary election.

"I made a decision for myself to resign on Wednesday after the next government meeting," he said in a televised statement.

Zelenskiy's surprise move is certainly controversial and follows repeated attempts by the majority in the current parliament to stymie his campaign promise for a snap election.

Since last month's election, Zelenskiy's opponents in the Rada sought to put off the inauguration close to the May 27 deadline by which the parliament can be dissolved.

And in a dramatic move last week, the Rada announced the collapse of the ruling parliamentary coalition. According to parliamentary rules, the chamber cannot be dissolved for 30 days after the governing coalition has been disbanded.

Zelenskiy's supporters argue that the Rada's actions are legally void because the coalition had long ceased to exist and that the Constitution, unlike the Rada regulations, does not contain such a rule.

Volodymyr Fesenko, head of the Kiev-based think-tank Penta, said Zelenskiy's announcement shows "political will for radical change."

"The legally dubious decision to disband parliament will certainly be contested in court but Zelenskiy has shown that it is going to be him who will lay down the agenda and that he will dominate the political landscape," he said.

Zelenskiy's landslide victory reflected Ukrainians' exhaustion with widespread corruption and the country's political elite. Before disbanding parliament, the 41-year-old Zelenskiy upended other Ukrainian political traditions on inauguration day.

He ditched the idea of a traditional motorcade to his inauguration, walking to the parliament Kiev through a park packed with people. Flanked by four bodyguards, the beaming president-elect gave high-fives to some spectators, even stopping to take a selfie with one of them.

At the end of his swearing-in ceremony Zelenskiy asked the Supreme Rada to adopt a bill against illegal enrichment and support his motions to fire the country's defense minister, the head of the Ukrainian Security Service (SBU) and the Prosecutor General. All are allies of Poroshenko.

That's when he dropped his bombshell about dissolving parliament. Zelenskiy told lawmakers they only have a few weeks to support his motions as that's as long as the current parliament has.

Two of the three officials he has asked to leave, Defense Minister Stepan Poltorak and SBU chief Vasyl Grytsak, promptly handed in their resignations.

Zelenskiy also told the Rada that the main goal for the presidency is to bring peace to eastern Ukraine, where government troops have been fighting Russia-backed separatists for five years in a conflict that has left at least 13,000 dead.

"I'm ready to do everything so that our heroes don't die there," he said. "It wasn't us who started that war. But we need to be the one to finish it."

The new president wrapped up his speech at parliament by referring to his career as a comedian.

"Throughout all of my life, I tried to do everything to make Ukrainians laugh," he said with a smile. "In the next five years I will do everything, Ukrainians, so that you don't cry."