A surprise 3-1 victory at QPR on Sunday cemented the Royals' position in the play-off places, opening up a four-point gap over Wigan in seventh.
And the German-born defensive midfielder, who qualifies to play for Jurgen Klinsmann's US side through his American father, wants to maintain his form to make sure he is on that plane to Brazil, and plying his trade in the top flight next season.
"Every player wants to play in the Premier League and the World Cup, and I am no different," Williams told The Daily Star.
"If I can achieve both, I could easily look back and say the year 2014 was the best year of my life.
"When you have the opportunity to play in the World Cup, you have to do everything possible to be included.
"I will also be doing everything in my power to prove my ability by helping Reading achieve promotion."
Williams is also hoping that his recent injury problems don't hamper his, or Reading's, progress coming into the final part of the season.
"It was hugely frustrating that injury prevented me from playing," Williams added.
"But at the moment I am happy, confident and looking forward to the next few months."