Nicolas Colsaerts has said that he is content with his second-round 72 at the US Open, which sees him two shots off the lead heading into the weekend.

The Belgian, who is part of a group of five players on one-over-par, feels that he is giving himself enough chances to make birdies around a tricky Merion set-up.

"I'm making good putts, [but] I still feel like I left a few out there," the 30-year-old told reporters.

"The key is to keep the ball in position, miss on the right side, give yourself opportunities all the time either for birdie or par.

"I thought I did that pretty well today under the conditions."

Billy Horschel and Phil Mickelson lead on one-under-par at the halfway stage.