President Clinton told Ukrainians yesterday they should make the most of what he said was their best chance in a thousand years to pursue prosperity and freedom.
In a rousing address to a crowd of tens of thousands in the capital, Kiev, Mr Clinton said President Leonid Kuchma had opened the way to a better future for the impoverished former Soviet state.
He also said the government was in good hands under the reformist Prime Minister, Mr Viktor Yushchenko.
"I have not lived what you have lived . . . I cannot tell you how to build your future," he told enthusiastic onlookers waving blue and yellow Ukrainian flags and the American stars and stripes in Mikhailivska Square.
"But I believe Ukraine has the best opportunity in a thousand years to achieve both freedom and prosperity."
Mr Clinton was in Ukraine for just six hours on the last leg of his week-long tour of Europe which also included Germany, Portugal and Russia.
"America will stand by you as you fight for a free and prosperous future," he said against the gold-domed backdrop of the St Michael monastery. "Russia is working to build a new society, but you the people of Ukraine are still here, stronger than ever," he added to enthusiastic applause.
A few dozen communists waved red Soviet flags in protest at Mr Clinton's visit. After his speech, concluded with the peal of bells from the cathedral, the US President shook hands with the crowd for more than 20 minutes.
In his speech, Mr Clinton also warned against complacency, repeating four times the Ukrainian phrase boritesya i poboryte!, "Do not give up and you will win!".
"Communism has lost in Ukraine," he said. "But a full commitment to free market democracy has not yet won."
Underlining Washington's desire to see Ukraine look to Europe for political solidarity, Mr Clinton said the West would keep its doors open.
"We reject the idea that the eastern border of Europe is the western border of Ukraine. Of course, your future is your own choice. But we can and we will keep the door to the transatlantic community of democracies open to Ukraine."
Earlier, Mr Clinton met Mr Kuchma and won an agreement to close the Chernobyl power plant, scene of the world's worst civil nuclear disaster in 1986.
Mr Clinton's warm reception and broad smile were a contrast to the more formal atmosphere at his meetings with Russian officials.
Before leaving Moscow he paid a courtesy call on Mr Boris Yeltsin. Mr Yeltsin welcomed "friend Bill" to his Gorky-9 residence outside Moscow with tea and cakes baked by his wife, Naina.
Mr Clinton returned to the US after his visit to Ukraine.