Oprah Winfrey says running a TV network is "10 times harder" than presenting her talk show.

The media mogul - who quit 'The Oprah Winfrey Show'after 25 years to launch her own network OWN - admitted after a week in the job she is finding it difficult to adjust and often needs to stop to "catch a breath".

Writing on her Facebook page, Oprah said: "I will say this; it's 10 times harder than doing my daily show. Doing that show felt like breathing everyday. Now I'm in so many meetings I sometimes have to step out and catch a breath."

However, Oprah is relishing the challenge and says she is not worried about the future of the channel.

She said: "@Woodsy1069 asked me on Twitter yesterday if I was "frazzled" by OWN's performance thus far.

"Nope, not frazzled. And I have faith that if I do what I'm supposed to-allow it to serve my purpose, and you, the viewer - it will succeed. But I see every challenge as an opportunity. So no shortage of opportunities here.

"Everyone in the cable business told me it would take 3 years. Some said 5. I've been here a week. Lorne Michaels, master creator/producer told me months ago, 'It won't start to come together until you're there.'

"So I made myself CEO and now in the trenches with Erik and Sheri who've masterfully run Harpo, now also Presidents of OWN. We're uniting and building our team."