Donald Trump has urged global businesses to invest in the US saying that "America is open for business, and we are competitive once again."

Speaking in his first visit to Davos for the World Economic Forum, he reiterated the need for trade agreements to be "fair and reciprocal", but added that "America first does not mean America alone."

Giving his address to a packed conference hall, Trump said: "I am here to deliver a simple message: There has never been a better time to hire, to build, to invest and to grow in the United States. America is open for business and we are competitive once again."

In a calm and steady speech, he raised the issue of North Korea, saying that countries should apply "maximum pressure to de-nuke the Korean peninsula."

In the first visit by a sitting US president since Bill Clinton in 2000, he raised domestic issues, including migration which has been a major talking point in the US.

He called for a "merit-based system" to end chain migration inside the United States.

Trump in questions afterwards, he thanked those who were pouring "millions of dollars" or even just "ten dollars" into the US.

Asked what experience from his past best prepared him for the presidency, he said that "being a businessman" was one of his key assets adding that he had "always been good at building things."

Trump was booed by some of the audience when he said he didn't realise hoe "nasty, mean, vicious and how fake the press can be."

On trade, he warned nations that he perceived to be taking advantage of the United States, saying that the US "will no longer turn a blind eye."

His speech didn't reveal any new thoughts or details about his future plans with his keynote speech sending a message to hard-working people from around the world, he said: "Let us send our love and our gratitude to them, because they make our countries run, they make our country great."

For Trump it was another chance to speak to world leaders and explain his vision for American and the world.

It was a calmer speech than his UN general assembly speech in which he attacked "rocket man" Kim Jong-un and Iran.

Donald Trump at the World Economic Forum
US President Donald Trump delivers a speech during the World Economic Forum (WEF) annual meeting on January 26, 2018 in Davos, eastern Switzerland NICHOLAS KAMM/AFP/Getty Images