The United States on Wednesday criticized China for handing an 11-year prison term to the brother-in-law of Nobel Peace laureate Liu Xiaobo and called on Beijing to free the writer and his wife.

A court in Beijing sentenced Liu Hui for alleged fraud in connection with a real estate deal. The sentence was handed Sunday just after US President Barack Obama and Chinese President Xi Jinping ended a closely watched summit.

State Department spokeswoman Jen Psaki said that the United States "is deeply concerned" over the sentencing of Liu Hui.

"We urge Chinese authorities to release Liu Xiaobo, as well as his wife Liu Xia, immediately and to guarantee Liu Xiaobo and his family members the protections and freedoms to which they are entitled under China's international human rights obligations and commitments," she said in a statement.

"As President Obama told President Xi in California last week, history shows that upholding universal rights is ultimately a key to success, prosperity and justice for all nations," she said.

Liu Xiaobo, who spearheaded a bold petition for democratic reforms in the communist nation, was also sentenced to 11 years in prison in 2009 on charges of "subversion."

He was awarded the Nobel Peace Prize in 2010. Chinese authorities tried to block news of the prize and put his wife under house arrest.

US Representative Chris Smith, who chairs the House Foreign Affairs subcommittee on human rights, told AFP after the weekend summit that Obama, as a fellow Nobel laureate, should have pushed Xi harder to free Liu Xiaobo and other jailed activists.

Both the Obama administration and Chinese officials had billed the summit, held at the Sunnylands resort in California, as a way for the two leaders to set a positive tone after Xi took full power in March.