Patrolling NATO warplanes and troops and police on the ground kept the threat of terrorist attack in view, although worries about half-finished stadiums and transport chaos faded into the background three days before Friday's opening ceremony.

Bush's arrival in Greece followed hard on the heels of expressions of confidence from world leaders and Olympic officials that Greek authorities had done everything possible to ensure the world's biggest sporting extravaganza is safe.

Bush, father of President George W. Bush and head of the official U.S. delegation to the Games, boarded a yacht owned by Greek billionaire Spyros Latsis in the northern port of Kavala.

British Prime Minister Tony Blair, Russian President Vladimir Putin and French President Jacques Chirac are among other world leaders due to attend the opening ceremony.

Patriot air defence missiles and thousands of surveillance cameras have been deployed in the biggest security operation in peacetime Europe to guard the first Summer Games since the September 11 attacks on the United States three years ago.

PALESTINIAN REASSURANCE

Marwan Abdelhamid, diplomatic representative in Athens for President Yasser Arafat's Palestinian Authority, said no true Arab or Muslim would carry out any violence against the Games.

"We...declare that any possible action against the Athens Olympics, by anyone invoking the name of Palestine will be considered by the whole of the Palestinian people as an action against Palestine itself," he said.

While U.S. team nutritionists itemised chocolate chip and cheeseburger diets of 5,000 calories per athlete, the lumpier mixture of sports and politics prompted visa bans on sports ministers from Myanmar and Zimbabwe on human rights grounds.

Belarus's man, told last week he would also not be welcome, announced he would direct the team from the benches, at home.

But Japan displayed the gracious face of diplomacy, helping Iraq return to the Olympic family in style with a donation of uniforms and shoes for Baghdad's team of 31 athletes.

"We have arranged with our sponsors to donate uniforms, windbreakers, socks, shoes, shirts and bags," said Japanese Olympic Committee President Tsunekazu Takeda.

DRUGS FLOOR KENYAN BOXER

Kenya's only Olympic boxer was expelled from the Games after becoming the first competitor to test positive in Athens for a banned drug.

"David Munyasia has been excluded from the Athens Olympic Games after testing positive for cathine, a prohibited stimulant," International Olympic Committee spokeswoman Giselle Davies told reporters.

The substance derives from the leaf of the qat plant, commonly chewed as a recreational drug in East Africa.

It was the first positive case among more than 200 dope tests conducted in Athens since late July among athletes arriving for the Games. Six others have been barred in the past few days for failing pre-Olympic tests elsewhere.

But amid the talk of politics, doping and terrorism, Olympic 100 metres champion Maurice Greene kept his focus firmly on timings and his place in history as the Athens Games moved closer to the sporting challenges at their heart.

One of the biggest names in Athens, Greene dismissed consecutive recent defeats by Jamaican rival Asafa Powell as irrelevant to his hopes of another gold medal and talked up his claim to be the greatest sprinter of all time.

"It doesn't matter what you do before the Games," said the American. "It doesn't matter what you do after. It only matters what you do on the two days of competition."

Retaining his Olympic crown will bolster Greene's claim to historic supremacy. But the man himself is already in no doubt.

Of forerunners such as Carl Lewis and Jim Hines, he said: "I don't think any of those people can stand up to my stats."

One Games highlight is sure to be the battle between the United States and Australia in the swimming, where first-time Australian Olympian Lisbeth Lenton burst into tears when she saw the pool where the contest commences on Saturday.

"But they were tears of joy," the 19-year-old said.

Greek Olympic officials said organisers were confident of selling all five million tickets for the two weeks of events.

The officials predict the Olympics will transform Greece into an "A-class" nation.

McDonald's hamburgers, Heineken beer, Visa credit cards and Coca-Cola are among multinational sponsors paying big bucks to boost their brands by association with the globally televised exploits of 10,000 athletes from 202 countries.