U.S. President Donald Trump's tweets are adding fuel to a "vicious cycle" of tensions on the Korean Peninsula, North Korea's vice foreign affairs minister told The Associated Press in an exclusive interview Friday.

The official added that if the U.S. shows any sign of "reckless" military aggression, Pyongyang is ready to launch a pre-emptive strike of its own.

Vice Minister Han Song Ryol said Pyongyang has determined the Trump administration is "more vicious and more aggressive" than that of his predecessor, Barack Obama. He added that North Korea will keep building up its nuclear arsenal in "quality and quantity" and said Pyongyang is ready to go to war if that's what Trump wants.

Tensions between Pyongyang and Washington go back to President Harry Truman and the 1950-53 Korean War, which ended in an armistice, not a peace treaty. But the heat has been rising rapidly since Trump took office in January.

This year's joint war games between the U.S. and South Korean militaries are the biggest ever; the USS Carl Vinson aircraft carrier has been diverted back to the waters off Korea after heading for Australia; and U.S. satellite imagery suggests the North could conduct another underground nuclear test at any time.

A U.S. Army tank moves during a military exercise in Paju, near the border with North Korea, in South Korea on Friday. (Ahn Young-joon/Associated Press)

Pyongyang recently launched a long-range ballistic missile and claims it is close to perfecting an intercontinental ballistic missile and nuclear warhead that could attack the U.S. mainland.

Many experts believe that at its current pace of testing, North Korea could reach that potentially game-changing milestone within a few years — under Trump's watch as president. Despite reports that Washington is considering military action if the North goes ahead with another nuclear test, Han did not rule out the possibility of a test in the near future.

Satellite pictures suggest North Korea is ready to detonate a nuclear explosion underground, as the country prepares to mark the the 105th birthday of its founder Kim Il-sung 1:40

"That is something that our headquarters decides," he said during the 40-minute interview in Pyongyang, which is now gearing up for a major holiday — and possibly a big military parade — on Saturday. "At a time and at a place where the headquarters deems necessary, it will take place."

The North conducted two such tests last year alone.

U.S., South Korea rehearsing 'decapitation strikes'

The annual U.S.-South Korea military exercises have consistently infuriated the North, which views them as rehearsals for an invasion. Washington and Seoul deny that, but reports that exercises have included "decapitation strikes" aimed at the North's leadership have fanned Pyongyang's anger.

Han said Trump's tweets have also added fuel to the flames.

North Korean soldiers visit a newly constructed residential complex after its opening ceremony in Pyongyang on Thursday. (Damir Sagolj/Reuters)

Trump posted a tweet Tuesday in which he said the North is "looking for trouble" and reiterated his call for more pressure from Beijing, North Korea's economic lifeline, to clamp down on trade and strengthen its enforcement of United Nations sanctions to persuade Pyongyang to denuclearize.

We've got a powerful nuclear deterrent already in our hands, and we certainly will not keep our arms crossed in the face of a U.S. pre-emptive strike. Whatever comes from the U.S., we will cope with it. We are fully prepared to handle it. - Han Song Ryol , North Korea's vice foreign affairs minister

Trump has threatened that if Beijing isn't willing to do more to squeeze the North, the U.S. might take the matter into its own hands.

"Trump is always making provocations with his aggressive words," Han said. "It's not the DPRK but the U.S. and Trump that makes trouble."

North Korea's official name is the Democratic People's Republic of Korea.

He added: "We will go to war if they choose."

Han said the sanctions approach is misguided and cited the opening ceremony of a sprawling new high-rise residential area in Pyongyang on Thursday as evidence that sanctions have failed to ruin the country's economy. Kim Jong-un presided over the ceremony before about 100,000 residents and a large contingent of foreign journalists who have been allowed in to cover the holiday.

Han dismissed the suggestion Trump made last year during his presidential campaign that he was willing to meet Kim Jong-un, possibly over hamburgers.

Military trucks carry soldiers through central Pyongyang as the country prepares to mark Saturday's 105th anniversary of the birth of Kim Il-sung, North Korea's founding father and grandfather of the current ruler. (Damir Sagolj/Reuters)

"I think that was nothing more than lip service during the campaign to make himself more popular," Han said.

"Now we are comparing Trump's policy toward the DPRK with the former administration's and we have concluded that it's becoming more vicious and more aggressive," Han said.

"Whatever comes from U.S. politicians, if their words are designed to overthrow the DPRK system and government, we will categorically reject them," he said.

Han said North Korea changed its military strategy two years ago, when the reports of "decapitation strike" training began to really get attention, to stress pre-emptive actions.

"We've got a powerful nuclear deterrent already in our hands, and we certainly will not keep our arms crossed in the face of a U.S. pre-emptive strike," he said. "Whatever comes from the U.S., we will cope with it. We are fully prepared to handle it."

How much such comments are bluster, or how realistic they are, is hard to gauge.

Later Friday, Chinese Foreign Minister Wang Yi said all sides must stop provoking and threatening and start taking a flexible approach to resuming dialogue. He said China is willing to support any such effort.

South Korea's Unification Ministry, which deals with relations with the North, declined to comment on Han's interview.

The Kremlin Friday said it favours diplomatic methods of resolution of all crises, including on the Korean peninsula.