The new U.S. ambassador to China said Wednesday he will consider what can be done to help Liu Xiaobo, China's imprisoned Nobel Peace Prize winner who has been diagnosed with late-stage liver cancer.

"Our heart goes out to him and his wife and we are interested in doing what can be done to see if it is possible," Terry Branstad said, when asked if the United States has spoken to China about allowing Liu to seek medical treatment in the place of his choice including the United States if necessary.

"We Americans would like to see him have the opportunity for treatment elsewhere if that could be of help," Branstad, a former Iowa governor, told reporters in the courtyard of his new residence in Beijing.

Branstad, who arrived in the Chinese capital on Tuesday, said however that it is necessary for Washington and Beijing to work together to address "these important human rights issues."

Noting his personal relationships both with U.S. President Donald Trump and Chinese President Xi Jinping, the new ambassador said he wants to act as a "go-between" to help deal with challenging issues from now on.

Liu, who has been jailed since 2009 for his writings advocating greater democracy, was recently taken from prison to a hospital in the northeastern Chinese city of Shenyang.

Since the transfer of Liu to the hospital became known this week, China has faced growing calls to immediately release him.

"(He) could not have surgery, could not have radiotherapy, could not have chemotherapy," his wife Liu Xia said in tears in a video clip posted on Twitter of her speaking to a friend via mobile phone about the activist's dire medical condition.

Liu Xia has been under house arrest in Beijing without trial since her husband's being awarded the Nobel Prize in 2010 in absentia.

But she was allowed to meet Liu, China's only Nobel Peace Prize laureate, at the hospital, one of their relatives told Kyodo News on Tuesday.

China has welcomed Branstad, who was sworn in on May 24, as an "old friend." He has developed personal connections with Xi over three decades of engagement with the Asian power.

Branstad, the longest-serving governor in U.S. history, first hosted Xi in Iowa in 1985, when the Chinese president was a county-level party leader.

On Wednesday, Branstad also said when he starts working with China some of his top priorities will be expanding trade between the two countries and dealing with the threat posed by North Korea.