The new US president is delivering a virtual address, one of the first major speeches of his presidency, at the World Economic Forum in Davos.

U.S. District Judge John Coughenour, a Reagan appointee, scheduled the session to consider the request from Arizona, Illinois, Oregon and Washington.

President Trump's executive order ending birthright citizenship is an attempt to change the longstanding interpretation of the 14th Amendment. It's already facing major legal challenges.