More than 100,000 U.S. prescriptions per week for the drug are being written, Chief Financial Officer Karsten Munk Knudsen said.

"We are eager to roll out in ex-U.S. markets, but of course we need to do it in a responsible and sustainable way," he said.

Earlier on Thursday, the company said it would halve the supply of starter doses of the drug in the United States for several months to cope with high demand.

Novo currently has two contract manufacturers producing Wegovy - one in Europe and one in the United States - and has signed up a third in the United States, which will start producing in the later part of this year, and the company hopes to get more, he said.

    "We continue to scale. It'll not stop there," he said.

(Reporting by Nikolaj Skydsgaard in Copenhagen and Maggie Fick in London; writing by Josephine Mason; editing by Susan Fenton and Mark Potter)

By Nikolaj Skydsgaard and Maggie Fick