Emanuel Ginobili, guard of the reigning Olympic champion Argentina, said on Tuesday that the United States and Spain were two best basketball teams at the Beijing Olympics and his team had tough hurdles ahead in defending the title.

Agencies Emanuel (Manu) Ginobili, Argentina basketball point guard beams to the camera after claiming the gold for basketball men in Athens.

"Every game is difficult," he told a news briefing of the FIBA Diamond Ball Tournament for Men 2008, but added the Americans and Spaniards were on top at the Games.

Argentina came up short against Spain, losing 90-88 to their Olympic rival in a close warm-up game on July 22 at the Palacio de los Deportes in Madrid, Spain.

"They are better than us," the 31-year-old shooting guard said of Spain. "They are confident."

The 2008 Diamond Ball tournament, an outstanding warm-up to the basketball tournament of the Beijing Olympics, tipped off Tuesday in Nanjing, southeast China. Argentina beat Iran 81-71 in the first game.

Argentina, which finished fourth at the 2006 World Championships, was considered one of the gold medal favorites in Beijing.

With head coach Sergio Hernandez being able to keep together the core of his team and a group of players breaking into NBA recent years, Argentina tries to better the teamwork to beat both the Americans and European powers.

Ginobli is the most well known Argentina's NBA players. His success with the San Antonio Spurs has established him as one of the world's premier players.

Agencies Ginobili (Spurs)  dunks in a game while played by Yao Ming, another top NBA int'l player in the league.

The Diamond Ball tournament features China, Argentina and continental champions from Africa, Oceania and Asia, namely Angola, Australia and Iran.

In addition, the European powerhouse and 2002 FIBA world champion Serbia will also leave its footprints in Nanjing.

(Xinhua News Agency July 30, 2008)