Ukraine's new President Petro Poroshenko has taken the oath of office in a swearing-in ceremony in the country's parliament in Kyiv.
Immediately afterward he told the audience that what Ukraine needs is peace, security, and unity.
He said he would soon visit east Ukraine and would come "with peace, with a project to decentralize power, and with guarantees for the free use of the Russian language in the region."
He also said he is willing to call local elections in Donbas. But he said Ukraine will always be a unitary state and no federalization would be allowed.
Poroshenko called on insurgents to lay down their arms, offered amnesty for those without blood on their hands, and said he would guarantee a corridor for mercenaries to leave the country.
And he condemned Russia's annexation of Crimea.
"Russia occupied Crimea. Crimea was and will be Ukrainian," he said to applause. "Yesterday, I firmly stated this to [Russian President Vladimir Putin] in Normandy. Crimea is and will be Ukrainian."
He also said Ukraine's citizens will not feel secure until relations with Russia are settled.
Turning to Ukraine's European aspirations, Poroshenko said he intends very soon to sign the economic part of an EU Association Agreement and sees it as a first step toward eventual full membership in the EU.
Among those attending the June 7 ceremony were U.S. Vice President Joe Biden, Belarus President Alyaksandr Lukashenka, and the Russian charge d'affaires in Kyiv.
Poroshenko succeeds Viktor Yanukovych, who was impeached by parliament in February after fleeing Kiev following three months of mass protests against his government.
Hours ahead of the inauguration ceremony in Kyiv, Ukrainian government forces were continuing to battle pro-Russian separatists in the east near Slovyansk and Donetsk.
The inauguration comes a day after Poroshenko met briefly and unofficially in France with Russian President Vladimir Putin during a commemoration of the D-Day invasion's 70th anniversary.
With reporting by Reuters and the BBC