Kim Jong-un is getting “very paranoid”, the US ambassador to the UN has warned amid growing concerns that Donald Trump’s war of words with North Korea could spark a nuclear attack.

In a round of interviews on Monday morning, Nikki Haley did not rule out a pre-emptive strike by the US on Pyongyang if it tests another nuclear device.

Ms Haley also praised China’s involvement in trying to pressure North Korea to cease missile testing.

She also criticised the North Korean leader, Kim Jong Un, as unstable and paranoid.

Ms Haley told NBC’s Today Show that “we are not going to do something unless he gives us reason to do something” – such as attacking a US military base or using an intercontinental ballistic missile”.

When asked what would happen if North Korea tests another missile or nuclear device, Ms Haley told NBC: “I think then the president steps in and decides what’s going to happen.”

“You can see he’s starting to get very paranoid… and we need to keep the pressure up.

“The United States is not looking for a fight – so don’t give us a reason to have one.”

The comments follow warnings that the U.S. faces a potential nuclear attack from North Korea within the next four years, according to Department of Homeland Security Secretary John Kelly.

Mr Kelly warned that the secretive state could attach a nuclear weapon to a missile that has the ability to reach the United States during Donald Trump’s first term as President.

He told CNN: “Clearly, there are countries on the planet that have a lot of nuclear weapons that would overwhelm any defence that we would deploy – Russia, as an example.

Department of Homeland Security Secretary John Kelly warned that North Korea could launch a nuclear strike against the U.S. (YouTube)

“But the minute North Korea gets a missile that could reach the United States and put a weapon on that missile, a nuclear weapon, the instant that happens, this country is at grave risk.”

Pressed on how long that would take, Mr Kelly added: “I think Mr Trump will be dealing with this in real terms before he starts his second term.”

Story continues

Mr Kelly’s warning comes just days after North Korea announced their own warning of a preemptive strike against the U.S. as tensions rise between Pyongyang and Washington.

MORE: Russia sends troops to North Korea border as tensions escalate

MORE: Jeremy Corbyn rules out second Brexit referendum in Labour manifesto

The Rodong Sinmun, the official newspaper of the North’s ruling Workers’ Party, said: “In the case of our super-mighty preemptive strike being launched, it will completely and immediately wipe out not only U.S. imperialists’ invasion forces in South Korea and its surrounding areas but the U.S. mainland and reduce them to ashes.”

U.S. Vice President Mike Pence, recently warned that the “era of strategic patience” with North Korea and its leader, Kim Jong-un, is over, adding that any attack would be met with an “overwhelming response”.

Both China and Russia have moved hundreds of thousands of troops to their North Korean borders.

Moscow’s deputy foreign minister Sergei Ryabkov said of the rising tensions: “Unfortunately, we have to admit that the risk of a serious conflict in this region has substantially increased.”

Top pic: