Described by Johnson as a "lifelong campaigner for democracy, human rights and peace", Liu was detained in 2008 after calling for democratic reforms. The Beijing government refused to let him seek treatment overseas despite Liu's wishes and global pressure. Liu, China's most famous political dissident, died during medical parole while serving a prison sentence for trying to overthrow the government.
Liu's wife, the poet and artist Liu Xia, and his other relatives could not be reached Thursday evening.
"It is with deep grief that I received the news of Liu Xiaobo's passing", Prime Minister Erna Solberg said.
Zeid also praised the Nobel laureate's widow, Liu Xia, who is being held by China under house arrest.
Worldwide human rights groups, Western governments and local activists had urged authorities to free Liu and grant his final wish to be treated overseas.
Amnesty International secretary general Salil Shetty said: "Today we grieve the loss of a giant of human rights".
Western leaders, rights groups and the Nobel Peace Prize committee expressed sorrow at the death of Chinese dissident Liu Xiaobo on Thursday, but reaction was muted in his homeland, where strict censorship made him less well-known than overseas.
UNESCO puts city of Hebron on its heritage in danger list
In an intractable and long-running battle, Unesco's recognition is, at least, a move in the right direction for Palestinians. The resolution was passed , said Haley, "despite protests by the United States, Israel and other countries".
The award was made in recognition of Mr Liu's "long and non-violent struggle for fundamental human rights in China".
But the government had warned repeatedly against interference and said Liu was being treated by renowned Chinese cancer experts.
Chair of the Norwegian Nobel Committee, Berit Reiss-Andersen, said in a statement: "We find it deeply disturbing that Liu Xiaobo was not transferred to a facility where he could receive adequate medical treatment before he became terminally ill".
The U.S. and German governments as recently as Wednesday had urged Chinese authorities to allow Liu to leave the country.
The Chinese Foreign Ministry's answer to foreign pressure had been that Liu's situation was an "internal affair".
The Shenyang Bureau of Justice said in a brief statement on its website that Liu had suffered multiple organ failure and efforts to save him had failed.
Former student leaders of the Tiananmen Square protests, Wang Dan and Wuer Kaixi, condemned the Chinese government following Liu's death.
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