Greta Thunberg refused to answer a question about dealing with haters at the World Economic Forum's (WEF) annual meeting, also known as Davos.

US President Donald Trump branded his impeachment trial a "hoax" in the Swiss resort of Davos on Tuesday, hours before senators were to start debating a push to remove him from office.

US President Donald Trump arrived in Davos on Tuesday for the annual WEF forum, where he was to give a keynote speech just hours before his impeachment trial kicks into high gear in Washington.