Novak Djokovic has praised Iga Swiatek, calling her a "warrior" as she moves into the third round of the US Open.

World No. 1 Swiatek has made a strong start to her bid to defend her title at Flushing Meadows. The 22-year-old dominated her first-round match against Rebecca Peterson, winning the match 6-0, 6-1. This was before winning in straight sets again against Daria Saville in the second round, 6-3, 6-4.

Meanwhile, Djokovic has seen similar success so far in the men's singles event, defeating Alexandre Muller and Bernabe Zapata Miralles in straight sets to get to the third round.

Speaking after his second-round victory, Djokovic praised Swiatek's fighting spirit, pointing out that the Polish player is too modest to admit it herself.

"Well, Iga has been dominating the women's game last couple of years, multiple Grand Slam winner. I love her, you know, devotion, dedication. Also, you know, maybe she's too humble to say, too modest to say, but she's got a great fighting spirit, no doubt," he said.

Djokovic went on to call the four-time Grand Slam champion a 'warrior.'

"She's a warrior, goes out there and, you know, doesn't give a single game. Actually, she has probably the most bagels of anyone in women's tennis the last few years.

"It speaks about how seriously and professionally she's taking every single point and game on the court. So that's very admirable. I really like that kind of champion spirit and mindset," he continued.

Swiatek will go on to face Kaja Juvan in the next round, while Djokovic will play against his compatriot and 32nd seed Laslo Djere.