American President Barack Obama has turned to one of the world's leading Reform rabbis to be his advocate for religious freedom across the world.

Rabbi David Saperstein, director of the Religious Action Centre, the American Reform movement's social action and justice arm, was nominated this week as an ambassador-at-large.

Mr Obama said that he was grateful that Rabbi Saperstein "has chosen to dedicate his talent to serving the American people at this important time for our country".

He is the first non-Christian to serve in the role, which was created in 1998. One senior figure in the Southern Baptist Convention, Russell Moore, described him as "a respected thinker and leader who brings gravity to this important role".

Rabbi Saperstein has led the RAC for more than 30 years and his latest book was Jewish Dimensions of Social Justice: Tough Moral Choices of Our Time.

In 2009, he was named by Newsweek magazine as America's most influential rabbi.