About 8,000 US National Guard troops from 40 states have been deployed to Washington for Donald Trump's inauguration, Euronews reports.

A security perimeter has already been set up around the National Gallery of Art, with soldiers controlling traffic and patrolling local subway stations.

Normally, nothing is planned for Inauguration Day other than the ceremony itself and related events. However, Trump promised to sign a number of decrees already on his first day in office.

Traditionally, the swearing-in ceremony takes place on the steps of the Capitol, but at the last minute it was decided to move it indoors because of the cold weather.