Barack Obama turns to some star power in the last days of the U.S. presidential campaign.
Wearing a dress emblazoned with the president's campaign slogan, "forward", pop diva Katy Perry warms up an audience in Milwaukee, Wisconsin.
This is one of the final campaign rallies for Obama, who is neck-and-neck with Mitt Romney in the race for the White House.
With the election just two days away, the president lit into his Republican challenger.
"Giving more power to the biggest banks, that is not change. Another $5 trillion dollar tax cut to the wealthiest Americans -- that's not change. Refusing to answer details about your policies until after the election -- that's definitely not change."
That was among the final salvoes in a race that is coming down to the wire.
Nationally, polls show Romney and Obama in a virtual tie.
At the same time they are separated by razor thin margins in four key swing states: Ohio, Florida, Virginia and Colorado.
