Donald Trump has claimed he and Kim Jong-un will “get it done together” amid continued controversy over the US’s stalled goal of North Korean denuclearisation.

“Kim Jong Un of North Korea proclaims ‘unwavering faith in President Trump.’ Thank you to Chairman Kim,” Trump tweeted on Thursday. “We will get it done together!”

The US president’s comments came after Kim reportedly said his faith in him was unchanged and that Pyongyang aimed to achieve denuclearisation within Trump’s first term in office, which is due to end in January 2020.

The South Korean national security adviser, Chung Eui-yong, delivered a letter on Wednesday to Kim from South Korea's president, Moon Jae-in.

Trump and Kim pledged to denuclearise the Korean peninsula at the Singapore summit in June but no details were agreed. Washington and Pyongyang have sparred since on what that means and how it will be achieved.

Reuters and AFP contributed to this report