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US presidential debate: Obama marks wedding anniversary

4 October 2012 Last updated at 02:26 BST

US President Barack Obama has opened the first of three televised presidential debates by wishing his wife Michelle a happy 20th wedding anniversary.

After being picked to speak first by a coin toss, Mr Obama said: "I just want to wish, sweetie, you happy anniversary"

Republican challenger Mitt Romney then added his own congratulations.