Taco Rice Dinner

1 lb ground beef
1 medium onion
1 can diced tomatoes
2 ½ cups liquid
1 cup rice
1 pkg taco seasoning
Brown beef and onion. Drain tomatoes and add water to make the 2 ½ cups liquid. Add tomatoes and liquid to hamburger. Add rice and taco seasoning. Bring to boil, then reduce heat. Cover and cook for 25 minutes.