The 33-year-old midfielder also acknowledged on Saturday that playing for AC Milan on loan from the Los Angeles Galaxy is a gamble.
Beckham, a former star for Manchester United and Real Madrid, said the move fulfills his dream of playing with a top Italian team and his goal of staying in shape during the MLS offseason in an attempt to keep a spot on England's team.
"I wouldn't take this opportunity if I didn't think that I could help the team and help the club," Beckham said during his introductory news conference at San Siro Stadium. "There are some great players out there. I don't expect to be starting on the first day because it doesn't happen that way."
England coach Fabio Capello has said it is not enough for Beckham to train with AC Milan -- he must also play to be considered for the national team.
"That is exactly the right thing a manager should do," Beckham said. "If any player is not playing in a team or playing at a top level, then playing at an international level is virtually impossible."
Beckham is bringing plenty of celebrity buzz with him to Italy. He is married to fashion icon Victoria Beckham -- who walked about the city Saturday in a basic black dress -- and the player himself has done underwear ads for the Milanese designer Armani. Beckham said Milan's status as a fashion capital did not enter into his decision.
"No, fashion had nothing to do with my choice in coming to Milan," he said. "The red and black shirt was the reason I came to Milan, and the history behind the club."
Victoria Beckham sat in the front row during the news conference wearing a slim-fitting short-sleeved dress, black gloves and stiletto heels. "Posh Spice" has recently signed as the spokeswoman for the new Armani lingerie line.
She and the couple's three boys will remain in Los Angeles for most of her husband's stint.
"They're going to be staying in school, but we're going to be coming over as much as we can," Victoria Beckham said. "We're very, very excited."
The loan begins Jan. 7 and expires March 9, Milan vice president Adriano Galliani said. The midfielder will start work after the holidays when he joins his new teammates at a training camp in Dubai on Dec. 29.
"He is in really great physical condition, I am told, and I believe that after the period of preparation in Dubai, I believe he will be up to playing," Galliani said.
Beckham cannot play competitive games with Milan until the transfer window opens in January. He will greet fans Sunday before a league match against Udinese and also will reportedly meet Italian Prime Minister Silvio Berlusconi, who owns the team.
But not everyone is pleased. Milan midfielder Gennaro Gattuso doesn't understand the point of this move.
"This Beckham thing seems very strange to me. Perhaps it would've been better and more right if he stayed for the whole season and signed a proper contract," Gattuso said this week. "To be here for six weeks to two months seems pretty strange."
Beckham will wear No. 32 at Milan.
"I think it was the first number they offered me and I said yes straight away because I would have worn any number to play in," he said.
Beckham made his opening remarks in Italian, struggling at the end to remember a few words.
"I really happy to be here," he said in English, before recalling the Italian he had been reaching for: "venire qui," or to come here.
"I have been very lucky in my career to play at some of the biggest clubs in the world, with Manchester United, Real Madrid and now AC Milan," he said. "There are no bigger clubs than those in the world."
Beckham is one short of the national team's appearance record of 108 games set by Bobby Moore, the 1966 World Cup captain. Capello said he will not select Beckham just so he can equal or pass that mark.
"It's important for Beckham, not for me," the England coach said. "He's a very important player. But if he will be in the squad it's because he is in a good spell of form."