Beckham, 32, the former English captain, said he did not see children waiting outside his Sydney hotel as he arrived under police escort for an exhibition match with his LA Galaxy team after flying from London by private jet.
"I would never have done that. Never have done, never will do. I'm more than willing to meet them wherever they want and at whatever time that they want," said a surprised Beckham when journalists asked him why he had snubbed the children.
Fourteen-year-old leukaemia survivor Emma Byers was left in tears after failing to give the former Manchester United and Real Madrid superstar a toy kangaroo as a welcome present.
"I'm quite happy to accept that he didn't see the children. The kids were off to the side. The cameras were flashing. It was a bit dark," her mother Anita told Australian Associated Press.
"I'd like to think he's a gentleman. I'm sure that if that's what he says, that was the case." she said.
Beckham's new team is in Sydney for three days to play an exhibition match against Sydney FC, to be watched by a sell-out 80,000 crowd at Telstra Stadium on Tuesday night.
His arrival comes just days after England's shock 2-3 Euro 2008 qualification loss to Croatia on Wednesday. Beckham came on as a second-half substitute to make his 99th international appearance.