The delay in the U.S. Senate's confirmation of Sung Kim as the next U.S. ambassador to South Korea could be due to a request by a Republican senator.

A diplomatic source in the U.S. says that did not name the senator who requested the delay.

Congress will go into recess Tuesday night and reconvene September sixth, which will push back Kim's confirmation process. If confirmed, he will become the first Korean-born U.S. ambassador to Seoul.