Despite Andy Murray's impressive season to date, world number one Novak Djokovic remains the favourite to win the US Open, according to Roger Federer.
While Djokovic continues to top the ATP rankings, world number two Murray has made significant inroads this season, claiming a second Wimbledon crown before going on to defend his men's singles gold medal at the Olympic Games in Rio.
Murray also reached the Western and Southern Open final, which he lost to Marin Cilic as his career-best 22-match winning streak came to an end.
Federer - out of action until next year as he overcomes a knee injury - has been impressed with Murray's form in 2016, but the 17-time grand-slam champion believes title holder Djokovic is the man to beat at Flushing Meadows.
"It hasn't really changed my opinion that Novak is the favourite, despite a few tough losses," Federer said at the launch of the Laver Cup.
"He did win [the Canadian Open] in Toronto. He has a great record against Andy and is a great hard court player, you see that in the conditions like here and at the Australian Open.
"I think the dome [the new roof over Arthur Ashe Stadium] will help him as well, as it will be more like Australia. Of course Andy is a great player in the wind, but then so is Novak.
"But I have been very impressed by Andy, what he has done this summer has been incredible. I hope he can keep that going. I think it will be a very exciting US Open and probably a great race between them until the end of the season."