Trump says he will meet North Korean leader Kim Jong-un later this year

US President Donald Trump on Wednesday said he would be meeting with North Korean leader Kim Jong-un later this year, days after scaling back joint US-South Korea military drills.

Trump also provided an unusually specific assessment of Pyongyang's nuclear capabilities, claiming the country now has "57 very power nuclear weapons".

Trump was responding to questions from reporters about his recent hints regarding communications with the North Korean leader, while on a tour of a new helipad at the White House.

While he refused to say whether the pair were exchanging letters, he said he gets "along with him very well."

"And you know what, the fact that I get along with him, that's a good thing not a bad thing. He has 57 very powerful nuclear weapons. Should have never allowed it to happen," he said, adding: "If I were president, I wouldn't have allowed it. But he's got them."

"I know Kim Jong-un very well, and he's going to be fine," he continued. "As long as we have a smart president, he's going to be fine. If we have a dumb president, then he's probably not going to be so fine."

Trump gave no further details on the planned meeting with Kim, which would be their first since Trump's first term in the White House.

The president's comments come just days after he announced that he had ordered US forces to scale back "costly" joint military drills with South Korea, which he said sent an "inappropriate and hostile" signal to Pyongyang.

In a post on Truth Social announcing the decision, Trump described North Korea as a "Country that, as long as Donald J. Trump has been President, has been unthreatening and respectful."

North Korea's nuclear programme

The head of the International Atomic Energy Agency (IAEA) said in April that North Korea was showing a "very serious increase" in its capability to produce nuclear weapons.

Speaking in Seoul, Rafael Grossi, the director general of the agency, said Pyongyang's nuclear programme was estimated at "a few dozen warheads."

"We have been able to confirm that there is a rapid increase in the operation of the Yongbyon 5-megawatt reactor," Grossi went on, adding that they had also observed a rise in operational activity at the reactor's reprocessing unit as well as "the activation of other facilities."

"All of them point to a very serious increase in the capabilities of the DPRK in the area of nuclear weapons," he said.

In July, North Korean state media reported that Pyongyang had also vowed to strengthen its nuclear force "in quality and quantity" as Kim touted the need for a strong military to guarantee "true peace."

North Korea has carried out six confirmed nuclear weapons tests since 2006.