European leaders hailed the smooth euro switch in Slovenia on Monday as the former Yugoslav country held a high-profile ceremony to mark the historic event, said reports reaching here from the Slovenian capital Ljubljana.

German Chancellor Angela Merkel, whose country holds the rotating EU presidency in the first half of 2007, said Slovenia's adoption of the euro was a "moving moment", especially considering that she personally saw two changes of currency -- first when Germany was reunified and then in 2002, when the euro was introduced.

European Commission President Jose Manuel Barroso said that the adoption of the euro was an important historic step for Slovenia and the European Union, as it proved that the eurozone was not a " private restricted club; the euro is truly a currency of the EU."

The single European currency euro has been Slovenia's only legal tender since Monday after two-week transition period in which the Slovenian tolar and the euro were in dual use.

The European Commission said last week that Slovenes were already making nearly all cash payments in euros. Almost 80 percent of tolars had already been deposited with banks and withdrawn from circulation. No notable problems were recorded, despite fears of massive price hikes.

On Jan. 1, 2007, Slovenia became the 13th country using the euro. The country of some 2 million is the first among the 10 EU newcomers that joined the pan-European bloc in 2004 to have fulfilled the rigorous economic criteria needed to join the euro zone.

Merkel said that Slovenia's successful switch to euro would encourage other EU newcomers to follow suit and reap the rewards of the euro, including the elimination of exchange cost and risk, relegating the threat of devaluation to history and encouraging cross-border trade and investment inside the eurozone.

Luxembourg Prime Minister Jean-Claude Juncker, head of the eurogroup, said that despite the many tangible benefits of the euro, citizens might still revel in nostalgia about their former currencies.

"It is crucial that we intensify our collective effort to explain to the citizens what the euro can do for them, and to caution them against asking the euro to perform where it simply cannot deliver," Juncker said.

Jean-Claude Trichet, president of the European Central Bank, praised Slovenia's achievement in economic development which saw its gross domestic product per person growing from 50 percent to almost 80 percent of EU's average between 1995 and 2006.

Slovenian Prime Minister Janez Jansa said the adoption of the euro was a big step for Slovenia, a small step for the European Monetary Union, and a step in the right direction at the right moment for the EU.

"Since the disintegration of Yugoslavia, Slovenia has walked a successful path of development and transition. Today marks the landmark in another successful step," he said.