Oxford have signed Australian winger Ryan Williams from Portsmouth on a two-year deal.

Williams, 27, was a free agent after turning down a new contract offer to stay with Pompey and returns to Sky Bet League One rivals Oxford after a season-long loan in 2013/14.

Oxford announced the signing on their official website and Williams said: “I’m really happy to be back at Oxford. It’s a very different place now to when I arrived: the training ground, the squad and the way the whole club is set up.

“They have gone so close to winning promotion in both of the last two seasons and they have done that by playing attacking football which I think is really going to suit me.

“I don’t mind my share of the hard work and I can’t wait to get back and start pre-season now.”

Williams, who started his career in England with Portsmouth, has won promotion from League One with former clubs Barnsley and Rotherham.

He scored eight goals in 42 appearances in all competitions during his first spell with Oxford.