'Europe has to do more' to fund Nato

US Vice-President Mike Pence is leading an American delegation to the Munich Security Conference this weekend.

Officials from around the world will be looking for clues into how President Trump's "America First" policy will affect international diplomacy, and the future of institutions such as Nato.

Mr Trump has already criticised European nations for not doing enough to fund the long-standing security alliance, something that past secretaries of defence have also pushed for, says ex-US defence chief William Cohen.

The BBC's Lyse Doucet caught up with Mr Cohen, a BBC World Affairs Analyst, on the sidelines of the conference.