France international Gallas, who won two Premier League titles and a League Cup winner's medal with Chelsea before moving to Arsenal, first trained with his new team-mates on Monday after agreeing terms on Saturday on a one-year deal with an option to extend.
"The atmosphere is great here,"
he told tottenhamhotspur.com.
"I like that and I'm just looking forward to playing as soon as possible and winning some games.
"It was not an easy decision [having played for Arsenal] but I am here now and I will give my best. What is most important to me is to play games and to give everything.
"I just want to be fit as soon as possible, train with my team-mates and play matches. I want to show everybody I am still here."
Gallas was not registered for European competition so will be unable to play against Young Boys in the second leg of Spurs' Champions League qualifier on Wednesday.
But the former Marseille defender, who has played in Europe's elite competition in each of the past seven seasons, believes that Tottenham can overturn their 3-2 deficit and progress to the group stages.
CROSSING NORTH LONDON CLUBS
Jimmy Robertson (Spurs 1964-68/Arsenal 1968-70): The only player to score for both teams in the derby
Steve Walford (Spurs 1975-77/Arsenal 1977-81): Just two games before Gunners boss Terry Neill took him to Highbury
Pat Jennings (Spurs 1964-77/Arsenal 1977-85): The Northern Irish goalkeeper won the FA Cup with both clubs
Sol Campbell (Spurs 1992-2001/Arsenal 2001-06): Suffered years of abuse from the Spurs faithful over his switch
"Spurs are ready for the Champions League, even though they lost the first game," he said.
"I have seen the game and the team showed character to come back. I am confident we will win that game.
"I have played many games in the Champions League. It is the best level to play at as you are up against the biggest teams and you can show how good you are.
"The atmosphere is so great. When you hear the music you just want to get on the pitch and battle for 90 minutes. It would be good for Spurs."
It is unknown when Gallas, who is roughly two weeks away from being match ready, will make his Spurs debut.
"What is most important to me is to play games and to give everything," he added.
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