The World Cup's toughest security headache may be a surprise visit by President Barack Obama, South Africa's police chief said Friday, joking that he secretly hoped the US side would bow out early.

南非警察部门负责人于上周五表示，世界杯最艰巨的安保任务可能会是美国总统贝拉克·奥巴马的突然来访，他开玩笑说自己暗暗希望美国队能早早淘汰。

"One challenge... is the American President who is coming, not coming, coming, not coming," national police commissioner¹（理事，委员） Bheki Cele told parliament in a briefing on security for the June 11-July 11 tournament（比赛，联赛） .

"Our famous prayer is that they don't make the second round," he told the parliamentary police committee. "They get eliminated and they go home because we are told that if they go to the second or third stage, the American president might come."

The United States is one of 31 visitor nations competing for the World Cup.

Forty-three heads of state have provisionally（临时地） confirmed their attendance at the tournament, the first on African soil, but Cele said the presence of the US leader would double security requirements for the event.

"That 43 will be equal to this one operation," he quipped.

Cele was briefing lawmakers on South Africa's security plan for the cup, which has met with approval from global police agency Interpol and security authorities of the 31 visitor teams.

Speaking in Washington last month, South Africa's foreign minister said Obama had indicated to President Jacob Zuma that he would attend the tournament if the United States reached the final.

"I remember him saying that he would maybe consider coming if the American team goes to the quarter-finals, might come if they reach the semi-finals, and will come to the finals," said Maite Nkoana-Mashabane.

The United States is in Group C with England, Slovenia and Algeria. The 2010 tournament will mark the country's ninth run at the World Cup. Its best ever showing in the tournament was third in 1930.