Kiev: Ukraine's new President Volodymyr Zelenskiy called snap parliamentary polls in his inaugural speech Monday and said his top priority is ending the conflict with Russia-backed separatists in the country's east.
The 41-year-old comedian was sworn in as Ukraine's youngest post-Soviet president a month after scoring a landslide victory over Petro Poroshenko with a campaign capitalising on widespread public discontent with the political establishment.
Zelenskiy -- whose only previous political experience is appearing as president in a popular TV show -- announced he would dissolve parliament in order to call early elections, originally scheduled for October.
"People must come to power who will serve the public," Zelenskiy said, after wrangling with hostile lawmakers whom he calls "petty crooks".
Prime Minister Volodymyr Groysman resigned in protest shortly afterwards, saying Zelenskiy had rejected his proposals and "chose another path." The legal status of Zelenskiy's move to dissolve parliament is uncertain but it is still likely to go ahead, political analysts said.
"There are no mechanisms or instruments to stop this decision," said analyst Mykola Davydchuk.
Zelenskiy said in his speech in Kiev that "our first task is a ceasefire in the Donbass," referring to the eastern separatist-controlled region, prompting a round of applause.
"We didn't start this war but it is up to us to end it," he said.
"We are ready for dialogue," he added, urging the handover of Ukrainian prisoners.
Russian Foreign Minister Sergei Lavrov responded that an exchange should include all prisoners from both sides, RIA Novosti news agency reported.
Zelenskiy said that Ukraine's "next challenge is the return of the lost territories," referring to Moscow-annexed Crimea and the separatists' self-proclaimed republics.
Switching to Russian in an emotive speech, he stressed that Ukraine must regain the trust of Russian-speaking people living there, who "are not strangers, they are ours, Ukrainians." Zelenskiy also called for the sacking of the head of the state security service, prosecutor-general and defence minister loyal to his predecessor, although this has to be approved by parliament.
Defence Minister Stepan Poltorak and the head of the SBU security service Vasyl Grytsak tendered their resignations on Monday. Foreign minister Pavlo Klimkin stepped aside last week.
Zelenskiy took a non-traditional route to his inauguration -- walking from his nearby home, after saying he wanted a less pompous ceremony.
Dressed in a dark suit, he exchanged high fives with supporters waiting outside, took selfies with them and even jumped up to plant a kiss on a supporter's forehead.
In his speech, Zelenskiy referred to his background as a comedian. "In my life, I've tried to do all I could to make Ukrainians smile," he said.
"In the next five years I'll do all I can so that Ukrainians don't cry." Uniquely for a first-time president, Zelenskiy has played the role before -- for laughs. He starred as a history teacher who was unexpectedly elected president in a television comedy series, "Servant of the People".
His newly-formed party is named "Servant of the People".
When the actor and comedian announced his candidacy in December, few took it seriously, but after a campaign largely waged through social media, he won more than 73 percent in the second round on April 21 against Poroshenko.
Poroshenko led Ukraine for five years, grappling with the fallout from Russia's 2014 Crimea annexation and the deadly conflict in the east.
Although he launched some reforms, he was criticised for failing to improve living standards or effectively fight corruption.
Zelenskiy has vowed to continue the country's pro-Western course but critics question how he will deal with the enormous challenges of the separatist conflict and ongoing economic problems.
The separatist authorities have indicated that they could be ready to negotiate with Zelenskiy.
Kremlin spokesman Dmitry Peskov on Monday said President Vladimir Putin has no plans to meet Zelenskiy and would not be congratulating him on his inauguration.
The Russian president will only "congratulate him on the first successes" in resolving the separatist conflict, he said, calling it a "domestic problem" for Ukraine.
Kiev and its allies accuse Moscow of militarily supporting the separatists, which it denies.
Earlier this month, Putin ordered an easing of procedures for Ukrainians living in the separatist regions to gain Russian passports, a move that caused uproar in Kiev.