PRESIDENT Trump has vowed the US will remain the “most powerful nation in the world” and bragged about its “stronger and more powerful” nuclear arsenal in a direct threat against North Korea online.

The hawkish leader — currently on a working holiday in New Jersey — also retweeted a Fox News article that claimed US air force jets in Guam are ready to “fight tonight” as rhetoric heats up against the rogue state.

“How we train is how we fight and the more we interface with our allies, the better prepared we are to fight tonight,” a US pilot said in the article.

My first order as President was to renovate and modernize our nuclear arsenal. It is now far stronger and more powerful than ever before.... — Donald J. Trump (@realDonaldTrump) August 9, 2017

...Hopefully we will never have to use this power, but there will never be a time that we are not the most powerful nation in the world! — Donald J. Trump (@realDonaldTrump) August 9, 2017

It comes as archived video from nearly two decades ago shows the President speaking to Tim Russert on Meet the Press when he was best known as a New York businessman. The footage shows him describe nuclear proliferation as “the biggest problem this world has” which he would “negotiate like crazy” to reduce.

MORE: Guam locals fear being ‘blown to smithereens’

“We can talk about the economy, we can talk about social security, but the biggest problem this world has is nuclear proliferation,” he said in comments before 9/11 and the emergence of the Islamic State.

He also talks about the urgency of addressing the North Korean situation before they had “weapons pointed all over the world and specifically at the United States.

Tim Russert interviewing @realDonaldTrump in 1999 about launching a pre-emptive strike against North Korea.

Could be key to his thinking. pic.twitter.com/PRbDA9r6Jp — Sven Henrich (@NorthmanTrader) June 20, 2017

“Look Tim, if a man walks up to you on the street in Washington ... and puts a gun to your head and says ‘give me your money’ wouldn’t you rather know where he’s coming from before he’s got the gun in his hand?” he asks.

“We have a country out there in North Korea which is sort of wacko, which is not a bunch of dummies and they are going and developing nuclear weapons.”

“Wouldn’t it be good to sit down and really negotiate something?

“Now if that negotiation doesn’t work, you better solve the problem now than solve it later, Tim. And you know it and every politician knows it and nobody wants to talk about it ... these people are laughing at us.”

The tough talk comes after US intelligence found North Korea had produced a nuclear warhead small enough to fit inside a ballistic missile, showing plans were much more advanced than previously thought.

President Trump said the country would face “fire and fury” like it had never seen before and North Korea threatened a missile strike against Guam.

Leaders in Europe and the US have called for calm, saying there is no “imminent threat” but expressing alarm at the escalation of rhetoric between the two countries.

A German Foreign Ministry spokesman says “further sabre rattling” and military measure won’t help solve the issue, while EU spokeswoman Catherine Ray said peace must be achieved through “peaceful means”.

On Tuesday, Guam residents — who live on American soil but are not allowed to vote for the President — spoke about their fear of an attack.

Governor of Guam, Eddie Baza Calvo, posted a video on YouTube telling residents not to worry and that “there is no threat to our island or the Marianas.”

He said he was working with the White House and assured his people an attack on Guam is “an attack or threat on the United States”.

“Guam is on American soil.”

“We are not just a military installation ... I want to ensure we are prepared for any eventuality.”