U.N. human rights experts urged China on Wednesday to release Liu Xia, the widow of Nobel Peace Prize laureate Liu Xiaobo, and allow her to seek treatment for deteriorating health, including traveling abroad.

The appeal came nearly a year after Liu Xiaobo died of liver cancer on July 13, 2017 while in custody, having been jailed in 2009 for "inciting subversion of state power."

Liu Xia, an artist and poet who suffers from depression, has been under effective house arrest since her husband was awarded the prize in 2010. She has never been charged with any crime and was last seen in public at his funeral accompanied by Chinese authorities.