Madison Keys was both heartened and frustrated by her performance in her French Open loss to Sloane Stephens, which she described as a marked improvement from her US Open final defeat to the same opponent.

Keys was unable to avenge her 6-3 6-0 loss to good friend Stephens at Flushing Meadows last year and, as she did in New York, produced an error-strewn display in the semi-final at Roland Garros.

But the scoreline was much closer, Stephens claiming a 6-4 6-4 triumph, and things could have been different had Keys not wasted a pair of break points at 2-4 in the first set.

"I think, you know, one of the things about the match today [Thursday], which makes me feel great in some ways and not great in others, is it was a couple points here and there. I mean, that's a lot better than last time I played her," Keys told a media conference.

"So there is that. But at the same time, it makes it a little bit more difficult to get over that just because I feel like I was so much closer."

Stephens will play world number one Simona Halep of Romania in the final and Keys sees the contest as a clash between two similar players.

Asked to rate her fellow American's chances, Keys replied: "I think it's going to be an incredibly tough match.

"They obviously both move really well. It's going to be, you know, who can stay in the point the longest.

"I mean, if she [Stephens] plays like she did today, I think she has a great chance."

Keys' focus now shifts to the grass, one of her favourite surfaces, and Wimbledon, where she will be looking to improve on her best showing, a run to the quarter-finals in 2015.

"I mean, I hope it carries over [her form]," she added. I feel good. I mean, I have a lot of good matches under my belt now. And going on to one of my favourite surfaces, I'm always happy to feel like I'm really confident in my game," she said.

"Even today, losing, knowing that I kept trying to do the right thing and I stayed in it till the very end, those are all really great feelings.

"So I go into grass season feeling really great, so hopefully that can all just carry over."