Zelenskiy Sworn In As Ukraine's New President

Volodymyr Zelenskiy walks to the parliament in Kyiv to take the oath of office on May 20.

Zelenskiy greets his supporters before the inauguration ceremony.

Zelenskiy takes selfies with supporters. The 41-year-old actor and comedian had no previous political experience before running for president.

Zelenskiy heads into the building of Ukraine's parliament, the Verkhovna Rada.

In his inaugural speech, the former comedian said he will try to ensure that "Ukrainians do not cry" during his term in office.

Zelenskiy receives the Ukrainian symbols of power.

Outgoing President Petro Poroshenko (left), who lost to Zelenskiy by a wide margin, and former President Viktor Yushchenko attend the inauguration ceremony.

The new president immediately called for the dissolution of parliament and the dismissal of top security officials including Prosecutor-General Yuriy Lutsenko, the defense minister, and the head of the Security Service of Ukraine, all seen as Poroshenko loyalists.

Spectators watch the inauguration ceremony.

Zelenskiy made reference to U.S. President Ronald Reagan, another actor elected to high office, saying: "Government is not the solution to our problem; government is the problem," a quote from Reagan's first inaugural address in 1981.

Zelenskiy also said that his top priority is negotiating a cease-fire in Ukraine's eastern Donbas region, where government troops are fighting Russia-backed separatists.