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Mitt Romney running mate Paul Ryan unveiled in Virginia

11 August 2012 Last updated at 23:32 BST

The Republican candidate for the American presidential election Mitt Romney has chosen a conservative congressman from Wisconsin as his running mate.

Paul Ryan chairs the powerful House of Representatives' budget committee.

He supports deep cuts in government spending and has pledged to reverse President Obama's healthcare reforms.

The BBC's North America editor Mark Mardell reports.