Lee Ae-ran holds letters addressed to U.S. first lady Michelle Obama and Secretary of State Hillary Clinton in front of the U.S. Embassy in Seoul on Thursday.

Lee Ae-ran, a North Korean defector and professor at Kyungin Women's College, on Thursday wrote to U.S. first lady Michelle Obama and Secretary of State Hillary Clinton in efforts to help dozens of North Korean defectors who were arrested in China and face repatriation.

Lee (48) delivered the letters to the U.S. Embassy in Seoul. "Please help us ensure the safety of our children, brothers, sisters and other relatives who are suffering after being arrested in China," she wrote. The U.S. Embassy acknowledged receipt of the letters.

Lee met Michelle Obama and Clinton in March 2010 as one of the 10 recipients of the annual Award for International Women of Courage from the U.S. State Department. At the time, Clinton praised Lee for having played a leading role in helping other North Korean defectors settle and get an education in South Korea.

"I believe the U.S. State Department gave me the award because it wanted to encourage me and therefore expected me to work harder to promote the human rights of defectors," Lee said. "I wrote the letters to fulfill the responsibility."

"People are fleeing North Korea to escape starvation, but many are arrested in China and sent back to the North, where they die miserably in political concentration camps or prisons," she said. China's repatriation of defectors to the North is "the most obnoxious form of cold-heartedness. It's just like handing over a poor person, who is asking for protection, to a robber," she added.

"Right after he took power, Kim Jong-il had even destitute people convicted of petty crimes shot dead," she said. "Kim Jong-un, too, will most likely handle the defectors arrested in China brutally to set an example because he is still consolidating his power.

Lee started a hunger strike in front of the Chinese Embassy in Seoul the same day to stop the Chinese government sending the defectors back.

After fleeing the North herself in 1997, Lee earned a doctoral degree in nutritional science and food management from Ewha Womans University, the first North Korean woman to do so. She has been raising funds for female and children defectors, while teaching at Kyungin Women's College since 2010.