Washington DC - President Donald Trump ominously said he no longer needed to think "purely of peace" after failing to win the Nobel Peace Prize and reiterated his intention to seize Greenland in a bizarre message to Norway published Monday.

"Considering your Country decided not to give me the Nobel Peace Prize for having stopped 8 Wars PLUS, I no longer feel an obligation to think purely of Peace," Trump said in a message to Norwegian Prime Minister Jonas Gahr Store.

He said although peace would still be "predominant," he would "now think about what is good and proper for the United States of America."

Store's office confirmed the authenticity of the document in an email to AFP.

Donald Trump Bipartisan US delegation defies Trump with striking show of support for Denmark and Greenland

In a written comment, Store underlined that the Nobel Peace Prize was not awarded by the Norwegian government.

"I have clearly explained, including to president Trump what is well known – the prize is awarded by an independent Nobel Committee," Store said.

Trump also reiterated his desire for control of Greenland, days after announcing tariffs against eight European countries that oppose his threats of annexation.

"Denmark cannot protect that land from Russia or China," Trump said, adding: "Why do they have a 'right of ownership' anyway? There are no written documents, it's only that a boat landed there hundreds of years ago, but we had boats landing there, also."

He concluded: "The World is not secure unless we have Complete and Total Control of Greenland."

Trump had campaigned hard to win last year's Nobel Peace Prize for what he claims are his efforts to stop eight wars.

Instead, it went to Venezuelan opposition leader Maria Corina Machado, who gifted Trump her medal after the US overthrow her nemesis, President Nicolas Maduro, in a violent coup at the start of the month.