New Ukrainian President Volodymyr Zelensky (center) takes a selfie with a fan as he walks to parliament to be sworn in as the country's sixth president since its independence in 1991, on Monday in Kiev. Photo: VCG

Former comedian Volodymyr Zelensky stepped into his new role as Ukrainian president with his inauguration on Monday, launching a new era for the country wracked by war and economic difficulties.

A month after scoring a landslide election victory against incumbent Petro Poroshenko, the 41-year-old became Ukraine's youngest post-Soviet president. 

In a ceremony in parliament, he placed his hand on a copy of the constitution and the Bible and pledged to "protect the sovereignty and independence of Ukraine."

He used his inaugural speech to announce that he is dissolving parliament, after wrangling with lawmakers in the lower house, in order to call early parliamentary elections, which had originally been scheduled for October.

"People must come to power who will serve the public," Zelensky said.

Critics had questioned whether Zelensky would be able to govern without a parliamentary majority. Even setting a date for his inauguration took weeks of negotiations with hostile lawmakers, whom Zelensky exasperatedly called "petty crooks."

Dressed in a dark suit and tie, the president took a non-traditional route to his inauguration - walking on foot from his home nearby, after saying he wanted a less pompous ceremony. 

In a sign of his more informal style, he exchanged high fives with supporters waiting outside and took selfies with them.

So far little is known about his precise policies after a campaign that capitalized on public disillusionment with the political establishment and promised to "break the system."

Uniquely for a first-time president, Zelensky had played the inauguration scene before - for laughs. He starred as a history teacher who was unexpectedly elected president in a television comedy series, Servant of the People.

Just a few months ago, the idea that Zelensky would be inaugurated for real seemed equally unlikely. 

When the actor and comedian announced his candidacy on December 31, few took it seriously, but after an unprecedented campaign largely waged through social media, he won more than 73 percent in the second round on April 21, trouncing Poroshenko.

Zelensky has vowed to continue the country's pro-Western course but his critics question how he will deal with the enormous challenges of the separatist conflict and ongoing economic problems.

Kremlin spokesperson Dmitry Peskov on Monday said Russian President Vladimir Putin has no plans to meet with Zelensky and would not be congratulating him on taking up the post.

He said that Putin would congratulate his newly elected counterpart if Zelenskiy makes progress in settling the conflict with separatists in eastern Ukraine and mending relations with Russia.