Obamas to meet Oprah

President Barack Obama and his wife Michelle will appear together on Oprah Winfrey's show next month.

It will be broadcast just a few weeks before the last ever episode - Oprah's ending her popular chat show after 25 years on air.

Orpah campaigned publicly for Obama, and helped raise millions for his presidential campaign.

Meanwhile advertising rates for the last ever Oprah show are being offered at a higher price than the finales of Lost and 24.

30 seconds of airtime for the May show have been priced at 1 million dollars - and could rise even further.

The most ever paid for a non-sporting event was the last episode of Friends - where adverts cost $2 million.