Earlier, a stand-off erupted with reporters who accuse the McCain campaign of shielding his running mate, Sarah Palin, who has not held a press conference in nearly four weeks of campaigning.

The Alaska Governor had her first contact with world leaders yesterday, meeting Afghan President Hamid Karzai and Colombian President Alvaro Uribe for about 30 minutes each on the sidelines of the United Nations General Assembly in New York.

At first, campaign aides told the TV producer and reporters in the press pool that follow Mrs Palin that they would not be admitted, as is normal, along with photographers and a television crew to photo-opportunities before her meetings with Mr Karzai and Mr Uribe. Under that scenario, Mrs Palin would get a public relations dividend of pictures posing with world leaders, but not have to take, or dodge, shouted questions.

Later, the McCain campaign backed down, amid suggestions the TV networks would boycott Mrs Palin's talks. Reporters were allowed to accompany photographers into her later sessions with Mr Uribe and former US secretary of state Henry Kissinger, with whom, her senior foreign policy adviser Stephen Biegun said, she discussed some of America's most sensitive international relationships.

In the brief moments when Mrs Palin was visible to the press  her aides allowed a single print journalist to watch the first minute of her afternoon sessions  she sought to forge a personal bond with Mr Karzai. He told Mrs Palin about his son, who was born in January 2007. With both of them smiling, and with Mrs Palin patting her heart, Mr Karzai told her his son's name was "Mirwais, which means 'The Light of the House' ".