Beckham said: "All that's on my mind at the moment is getting myself fit.
"If I'm fit, obviously I have to play a few games before I even think about going home to England to play for the country.
"But my main priority at the moment is getting myself fit and getting myself playing for the Galaxy.
"Getting on the training pitch, to be honest, that's my biggest goal at the moment. Hopefully then, I'll be able to get a few games in and play for the country."
Beckham has said he has no regrets about playing while hurt in his final games for Real Madrid - despite tonight's game likely to be the fourth game he has watched from the sidelines since his token debut as a 78th minute substitute in a friendly against Chelsea on July 21.
"Then I played the last game of the season for Real Madrid with three injections to numb my ankle so you can imagine what my ankle looked like after the game. I ripped the ligaments in that last game so it was a bit of a mess.
"Then I went on holiday to recuperate and then when I arrived in LA it was the first time I really had treatment apart from about a week of fitness work that I was doing in the south of France.
"I personally have never agreed with any injections and anything that could be unnatural. I like to feel naturally fit going into games. But I think because we were going for the league title and we needed to win the last two games I would have done anything to play in that game.
"It wasn't healthy, it wasn't maybe the right thing to do in the long term but I did it and at the end of the day I'm glad I did it. I played in a game for 65 minutes and we ended up winning the league.
"It's something I did at the time and it's obviously not done me much good leading up to these last few weeks but I did and that's it."
Beckham, 32, began his running work as the rest of the Galaxy trained in Toronto having flown in from Los Angeles in the early hours of the day.
"Fitness-wise I'm fine, it's just the ankle is still swollen. I'm having deep tissue massage every day and at the moment running in straight lines is fine but that's not going to help me in a game.
"You need to be right. There's no point in me coming back and playing a game when people are expecting me to be playing at the high level I can and do. I'm here for five years and maybe longer and it needs to be right.
Beckham said he hoped the ankle would be healed in "maybe a week to 10 days", casting doubt on whether he would even face DC United on Thursday night.
"Today, running like I did was a huge step for me because I haven't really been able to move on it at all.
"The problem is it being my left ankle. The way I strike the ball puts a lot of stress on my left ankle. Maybe if it was the right one it would be a lot easier but being the left one there's still a lot of stress. And I never play with strapping or tape on my ankles so that doesn't help either.
"But it would be nice to play some part in the game in Washington but I'll just have to keep my fingers crossed and work at it."