"Our way to the future is the way of a united Europe. We, along with the people of Europe, belong to one civilisation. We share similar values," Yushchenko told hundreds of thousands in Independence Square after his swearing-in in parliament.
In his 20-minute address he made no direct mention of Russia, where he meets Kremlin leader Vladimir Putin on Monday on his first foreign trip abroad before launching a tour of western and central Europe. But he said Ukraine would act strictly in its own interests.
"Our place is in the European union," Yushchenko said, his wife standing with their five children nearby. "We are no longer on the edge of Europe. We are situated in the centre of Europe.
"Ukraine will not be a buffer zone or a testing ground for anyone else," he said.
Yushchenko is to meet Russia's
Putin on Monday
"We are prepared to respect the interests of other states. But for me and for you, national interests are above all else."
Upholding Russian ties
Yushchenko, who won last month's re-run of a rigged poll after weeks of vast street protests, had pledged to move closer to the West while upholding ties with Russia.
Aljazeera's correspondent in Kiev said Yushchenko will have to tread carefully in his dealings with Moscow as Ukrainian economy relies heavily on its Russian neighbour - namely in oil and gas.
The former prime minister and central banker recognised that he had to fulfil the high expectations of supporters.
"Our choice resulted in high expectations. These are fair.
"They are absolutely realistic," he said.
"We have everything to succeed. The riches of our land are countless, the talents of our compatriots are respected all over the world ... we are opening a new page of Ukrainian history and it will be a beautiful page."