US President Donald Trump is deeply saddened to learn of the death of Liu Xiaobo, the Chinese Noble laureate, the White House has said. 61-year-old Liu, who was awarded the 2010 Nobel Peace Prize while in jail and was represented by an empty chair at the ceremony in Oslo, died yesterday due to multiple organ failure following a battle with cancer while still in custody. "President Donald J Trump was deeply saddened to learn of the passing of Nobel Peace Prize laureate and prominent Chinese political prisoner Liu Xiaobo," the White House Press Secretary Sean Spicer said. "The President's heartfelt condolences go out to Liu Xiaobo's wife, Liu Xia, and his family and friends. A poet, scholar, and courageous advocate, Liu Xiaobo dedicated his life to the pursuit of democracy and liberty," Spicer said in a statement. Today the world lost a hero of liberty and freedom, said Senator Ted Cruz, the Republican Senator from Texas. Liu Xiaobo, a voice for the voiceless and defender of the oppressed in Communist China, passed away. Although the physical cause of his death was cancer, Dr Liu's primary battle was one of the soul, he said. Ever since leaving the safety and comfort of America to lead the protests at Tiananmen Square in 1989, Liu sealed his fate as a persistent focus of persecution from the authoritarian PRC, Cruz said. From 'reeducation through labor' and deprivation of property to unjust imprisonment and physical abuse, Liu bore the brunt of the Communist Party's wrath for daring to challenge their immoral system of political oppression in his coauthoring of 'Charter 08', a manifesto of Chinese freedom that reverberates today more than ever, he added. Senator John McCain said the death of Liu Xiaobo in a Chinese prison represents an egregious violation of the fundamental human rights for which Dr Liu spent his life. "Unfortunately, and as Dr Liu would have wanted everyone to remember today, this is only the latest example of Communist China's assault on human rights, democracy, and freedom," he said. A Nobel Peace Prize laureate who was wrongly imprisoned by the Chinese government for nearly a decade, Liu was a champion for human rights throughout his life, McCain said. From protesting at Tiananmen Square to authoring a human rights manifesto for which he was unjustly jailed, Dr Liu was relentless in his pursuit of a democratic China. As he suffered from late-term liver cancer in prison, the Chinese government's delay in treatment was the last barbaric violation of Dr Liu's human rights, he said. The news of Liu Xiaobo's death today is beyond tragic\u2014for his beloved wife Liu Xia, for his family, and for the millions of supporters of his courageous efforts to champion human rights and democracy in China, said Senator Marco Rubio. "As we mourn Liu Xiaobo's death and pray for his family, there are urgent matters that require high-level diplomatic attention in the coming days. "Dr Liu's family must be given his remains and permitted to honor and bury him as they see fit. Liu Xia must immediately be granted an exit visa and permitted to leave China for a country of her choosing," he said. "There should be an independent investigation into the circumstances surrounding Dr Liu's death, his treatment in detention, the timing of the diagnosis of his late-stage liver cancer, and countless other questions that need to be answered. "The Chinese authorities complicit in his unjust imprisonment and death should be immediately sanctioned and their assets frozen under the Global Magnitsky Act," Rubio said. Congressman Sander Levin said Liu Xiaobo was an inspirations to millions of people around the globe. "History will remember Liu as a giant who sought to advance the debate on democratic governance, human rights, and rule of law in China, and for the way Chinese authorities mistreated him and other human rights advocates," he said.