The 23-year-old joins from Norwegian top-flight side Kolbotn IL.

Mikalsen, a Norway under-23 international, is the second goalkeeper to join promoted United this summer with England goalkeeper Mary Earps arriving from Wolfsburg in July.

"Aurora is a fantastic young talent with a lot of potential," United manager Casey Stoney said.

The Red Devils start their first WSL season against cross-city rivals Manchester City at the Etihad Stadium on Saturday.