Former U.S. President Bill Clinton made his campaign-trail debut on for wife Hillary Clinton on Tuesday where is said that he would do all he can to help her win the White House.

He praised her ability and toughness and said that he would do all he could to help her win the White House.

The appearance at a rally on the Iowa state fairgrounds was the public campaign unveiling for the couple.

Bill Clinton had limited his previous campaign help to behind-the-scenes advice and joint appearances at closed fund-raising events.