"If we won the World Cup and I equalled the caps record in the final, that would be an amazing way to finish, but I'd still find it hard to walk away from playing," the LA Galaxy midfielder told Saturday's edition of Britain's The Times newspaper ahead of the MLS Cup final on Sunday.
"Even if that dream came true, I'd still make myself available to play for my country. I'd love to still be involved in some way, whether it's actually playing a game or not.
"My passion for the team and the country is that strong. That's never going to change," added Beckham who could equal goalkeeper Peter Shilton's record of 125 caps if he plays regularly and England reach the World Cup final next July.
Earlier this month, Beckham agreed a deal to rejoin AC Milan on loan from the Galaxy in January thereby boosting his hopes of a place in the England squad for the 2010 tournament.
"I'm dedicated to going to South Africa and wouldn't leave my family for six months if I wasn't," added Beckham, whose family plan to stay in California when he moves to Milan.
"It's not something I'm looking forward to. I don't want to be away from my wife and children for that length of time but it's probably the last time I'll do it.
"I'm so honoured that Milan have given me the chance to go back, but the hope of playing for England is the only reason I'm doing it."
