The Chinese hospital treating Nobel Peace Prize-winning dissident Liu Xiaobo, who was recently diagnosed with late-stage liver cancer, said Wednesday that his condition has worsened and is now life-threatening.

The First Hospital of China Medical University, to which 61-year-old Liu was transferred from prison for treatment, said he is "critically ill" with multiple organ failure and his family has refused to insert a breathing tube needed to keep him alive.

Despite nearly three days of active anti-infection treatment, the hospital said Liu's liver condition continued to deteriorate and he developed blood clots.

"The patient's condition has progressively worsened, with renal failure, subacute hepatic failure, respiratory failure, spontaneous peritonitis, septic shock, partial intestinal obstruction and disseminated intravascular coagulation," it said.

The hospital in the northeastern Chinese city of Shenyang, guarded by numerous plainclothes police officers, said on its website his family has acknowledged his dire condition and signed a waiver.

Fellow dissident Hu Jia told Hong Kong's public broadcaster RTHK that the family declined intubation because otherwise it would mean Liu would never be able to leave his sickbed.

Despite growing pleas for Liu to be allowed to travel abroad with his wife for treatment, China has adamantly maintained that Liu's case is a domestic affair in which foreigners should not interfere.

China has also said he is too sick to be transferred to anywhere else, although American and German specialists, who were permitted to see Liu at hospital, said over the weekend that he could be moved abroad safely.

The Hong Kong-based Information Center for Human Rights and Democracy earlier Wednesday quoted an unnamed family source as saying that Liu has been improving after undergoing dialysis Tuesday and was conscious on Wednesday morning.

A worldwide signature collection campaign has reportedly gathered more than 30,000 names calling for freedom of Liu, who was sentenced to 11 years in prison in December 2009 for "inciting subversion of state power" by helping draft a blueprint for political change, known as Charter 08, calling for democracy, human rights and the rule of law in China.

He was awarded the Nobel Peace Prize in 2010 in absentia.

On Wednesday, Taiwanese President Tsai Ing-wen joined the growing call for Liu's and his family's freedom and said the self-ruled island, which has high tensions with Beijing, is ready to provide assistance as much as possible.

German government spokesman Steffen Seibert urged the Chinese government to immediately allow him and his wife, Liu Xia, to leave for abroad and reiterated that Germany stands ready to host the couple and medically treat him.

U.S. State Department spokeswoman Heather Nauert said Tuesday Washington will continue to request Beijing for "his full parole and also for the release of his wife."

"I understand that his wife, who had been under house arrest, was able to be with him at the hospital. We're happy about that, however, we continue to call on China to release him so that he can receive medical treatment wherever he desires," she said. "If it's in the United States, I think we would certainly welcome that."

An opinion editorial carried by the Global Times, a mouthpiece under China's state-run People's Daily, criticized the "Western forces" for politicizing Liu's treatment.

"Foreign governments and institutes can give medical advice, but they must respect the final decision by China's prison authorities and medics," it said. "Western forces are not persuasive in reasoning. What they care about is not Liu's treatment, but transferring him abroad. This is a political charade."

Supporters from across China have been under surveillance or warned not to visit Liu in hospital, for fear that his death could upset social stability, blogger Ye Du was quoted by Hong Kong's Cable TV as saying.

In Hong Kong, 24 pro-democracy camp lawmakers submitted a petition letter to the Legislative Council, urging it to press the Chinese government to let Liu go abroad for treatment, while a marathon sit-in protest at Beijing's representative office in the city is ongoing.