Prague - US President Barack Obama arrived in Prague Saturday, the fourth stop on his five-country tour of Europe, where he is scheduled to meet EU leaders and deliver a key public speech on nuclear non-proliferation.

Czech President Vaclav Klaus and outgoing Prime Minister Mirek Topolanek greeted the US presidential couple on the red-carpeted tarmac, minutes after their Air Force One plane landed at Prague's international airport.

The US president arrived some two hours later than scheduled owing to prolonged talks at a NATO summit in Strasbourg, France.

Obama is to address Europe on Sunday - a highlight of his stop in the Czech Republic - with historic Prague as his backdrop. The event comes as countries across Europe commemorate two decades since the collapse of Communism.

The president has said he will unveil his plan towards ridding the world of nuclear arms.

Also on Sunday, he is set to meet leaders of the European Union for the first time since taking office. The Czech Republic hosts the top-level summit as it holds EU's rotating presidency until June 30.

Obama, who has already met leaders of European heavyweights such as Britain, Germany and France during this trip, is to hold bilateral talks with Polish and Spanish leaders and European Commission President Jose Manuel Barroso.

The president's schedule pays little attention to his Czech hosts, a source of "mild" disappointment in Prague's corridors of power, sources said.

The presidential couple plans to dine privately in the so-called city of a hundred spirals on Saturday, declining separate invitations by president Klaus and outgoing Prime Minister Mirek Topolanek.

A bilateral meeting with the two Czech leaders is set to open Obama's busy Sunday schedule.

It is a marked departure from the treatment Czech leaders received under the previous administration, which saw George W Bush visit Prague twice. Obama is the fourth US president to pay a visit to the Central European country of 10.3 million since Communism fell in 1989.

The visit by the world's political superstar has been tainted by the collapse of Topolanek's government and the premier's harsh appraisal of Obama's economic rescue plans last week. Topolanek likened US measures to combat the global financial crisis to "a road to hell."

However, before his departure for Turkey, Obama is to find time for a meeting with the symbol of anti-Communist resistance, former Czech president Vaclav Havel.

And even Mlada Fronta Dnes, a daily newspaper which has backed the Bush administration's initiatives in Eastern Europe, ran a triumphant headline on Saturday, simply reading "The O- Day."

The city has beefed up security measures, which include welding manhole covers shut. Tight security measures will also accompany Sunday's EU-US summit and public speech.

Spectators will undergo a security check similar to that at airports and are forbidden to bring items that could serve as weapons such as aerosol sprays, umbrellas and placards.

Obama's visit was preceded by a quiet, small protest on Saturday against plans to place a US military bases on Czech soil as part of the US missile shield.

Czechs hope that Obama would issue a clear verdict on the fate of the project, pushed by the Bush and Topolanek administrations but opposed by Russia and unpopular with the Czech public. Sources say he will stay away from such an announcement. (dpa)