US President Donald Trump will show off his new "Board of Peace" and meet Ukraine's leader at Davos on Thursday -- burnishing his claim to be a peacemaker a day after backing off his own threats against Greenland.

Trump abruptly announced on Wednesday that he was scrapping tariffs against Europe and ruling out military action to take Greenland from Denmark, partially defusing a crisis which has shaken the meeting of global elites.

On his second day at the Swiss ski resort, Trump will seek to promote the "Board of Peace", his controversial body for resolving international conflicts, with a signing ceremony for the organisation's charter.

The fledgling board boasts a USD 1 billion price tag for permanent membership and Trump has invited leaders including Russia's Vladimir Putin, Israel's Benjamin Netanyahu and Hungary's Viktor Orban to join.

"I think it's the greatest board ever formed," Trump said Wednesday as he met Egyptian President Abdel Fattah al-Sisi, another of the leaders who have agreed to join.