Victoria Azarenka has confirmed she will miss Belarus' Fed Cup final against United States due to the custody battle over her son.

The 28-year-old has not played since losing in the fourth round of Wimbledon to Simona Halep in July, and pulled out of the US Open as she was unable to leave her son Leo behind in California.

Reports earlier this week suggested Azarenka would also miss the final in Minsk this weekend, and she has now confirmed her absence via a post on Twitter.

"As you probably saw this week, I will not be able to be part of the Fed Cup final this year," she wrote.

"It is heart-breaking for me to not have a chance to play and help Belarus in the final, but unfortunately, my current custody situation is keeping me in California.

"Even though I will not be in Minsk for the final, my heart is always with my country and my team and I will cheer for them from afar.

"While it has been a tough year for me, I am already looking forward to 2018 and playing before my fans very soon.

"As always, I want to send you my gratitude for the support you give me every single day with your notes and messages. I will be back strong and better than ever!"