Yushchenko told a crowd of several thousand gathered for a religious service in Kyiv today that his government remains devoted to pro-democratic principles and is committed to joining the EU and NATO.
"By the will of the people, our country's course toward membership in the European Union and NATO will be carried through," Yushchenko said. "And most importantly, I reiterate and guarantee that Ukraine's democratic, liberal, and national choice is irreversible and unconditional."
A photo gallery of key events in the 15 years since Ukraine declared independence (Flash required)
Yushchenko said that Ukrainians have learned over the past 15 years of independence to be "a people and a nation," and said they form the basis of a "mature society."
He called for greater unity and said debate over the national language and religion should be dropped "once and for all."
"There is and will be no alternative to the Ukrainian language as the state language and as the language of official communication in Ukraine," he said. "It is the language of our freedom."
The significance of the anniversary was not lost on Ukrainians young and old, at home and abroad.
Proud To Be Ukrainian
Tetyana Korniyenko, a 15-year-old student from Dnipropetrovsk, said that she is proud to be a citizen of an independent Ukraine.
"I am free; I can do what I want," she told RFE/RL. "I've never lived in the Soviet Union; I don't know how it was there. My parents told me that if living conditions improve, it will be a very good time [to live]. Now we are a separate country and we should to take care of ourselves on our own. Nobody is going to help us any longer. Ukraine strived to be independent and became independent. We ourselves are responsible for our actions, and the whole world knows this."
But Jaroslava Hartyani, who heads the Association of Ukrainian Culture in Hungary, said her native Ukraine could have progressed further as an independent country.
"The saddest thing for me is that on the 15th anniversary of Ukraine's independence the issue of the loss or preservation of independence is still on our agenda," she said. "This is perhaps the only country where such an issue is still being discussed."
Tragedy Clouds The Party
Celebrations were muted in the wake of the August 22 tragic air crash near Donetsk, in which 171 people traveling on a Russian airliner were killed on their way from the Russian Black Sea resort of Anapa en route to St. Petersburg.
Some events scheduled as part of Ukraine's independence celebrations have been postponed until this weekend as a result of the crash.Addressing several thousand people gathered in central Kyiv for a religious service, President Viktor Yushchenko reiterated his government's pro-democracy policies and Ukraine's bid to join the EU and NATO.