When wished happy birthday, most of us perhaps reply with a polite but simple thanks.

Not so Kim Jong-un, it seems.

After Donald Trump sent well wishes to the North Korean dictator this week, the dictator has responded by apparently telling the US president he must be “dreaming” if he believes such a message might help revitalise stalled nuclear talks.

It is not clear if a card and present – a vase, say? – might have done the trick.

“Although Chairman Kim Jong-un has good personal feelings about President Trump, they are, in the true sense of the word, ‘personal’,” said Kim Kye Gwan, the country’s foreign ministry adviser, after Pyongyang received the birthday note. “The Chairman of the State Affairs Commission would not discuss the state affairs on the basis of such personal feelings, as he represents our state and its interests.”

Kim Jong-un: Power in pictures Show all 20 1 /20 Kim Jong-un: Power in pictures Kim Jong-un: Power in pictures Kim Jong-un rides a horse during snowfall in Mount Paektu in this image released by North Korea's Korean Central News Agency on 16 October 2019 Reuters Kim Jong-un: Power in pictures Kim Jong-un visits the newly built Pyongyang Orphans' Primary School on 2 February 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects a women's company under Unit 5492 of the Korean People's Army in November 2019 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects the test-fire of intercontinental ballistic missile Hwasong-14 at an undisclosed location in July 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un celebrates the successful test-fire of the intercontinental ballistic missile Hwasong-14 at an undisclosed location in July 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects a potato at the Samjiyon Potato Factory in North Korea in October 2018 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un rides a horse through a forest in this image released by North Korea's Korean Central News Agency on 16 October 2019 EPA Kim Jong-un: Power in pictures Kim Jong-un inspects a block of frozen fish at a processing facility in North Korea in November 2018 Reuters Kim Jong-un: Power in pictures Kim Jong-un celebrates the succeful launch of a strategic submarine-launched ballistic missile in August 2016 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un shakes hands with Donald Trump as they meet for the first time at the Capella Hotel on Sentosa island in Singapore in June 2018 Reuters Kim Jong-un: Power in pictures Kim Jong-un and Donald Trump share a glance as they meet in the Demilitarised Zone in Panmunjon, Korea in June 2019 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects mushrooms at Pyongyang Mushroom Farm AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects a super-large multiple rocket launcher ahead of a test in September 2019 Reuters Kim Jong-un: Power in pictures Kim Jong-un inspects an apple farm in South Hwanghae Province in September 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects an apple farm in South Hwanghae Province in September 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects dental wares at a newly built factory in June 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un visits Farm No 1116 in September 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un visits a motor factory in November 2017 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un rides a horse during snowfall in Mount Paektu in this image released by North Korea's Korean Central News Agency on 16 October 2019 AFP/Getty Kim Jong-un: Power in pictures Kim Jong-un inspects the Command of the Strategic Force of the Korean People's Army at an undisclosed location in August 2017 AFP/Getty

The unusual rebuff comes after Mr Kim – who is believed to have turned 36 on 8 January – earlier opened the new year by expressing deep frustrations over the lack of progress with negotiations between the two countries.

He had previously said he was planning a “Christmas gift” for Donald Trump – widely interpreted to mean a new ballistic missile tests – although Mr Trump himself has appeared sanguine about the threat.

“Maybe it’s a nice present,” he told an armed forces rally. “Maybe it’s a present where he sends me a beautiful vase as opposed to a missile test. I may get a vase. I may get a nice present from him. You never know.”

Pyongyang has largely held off nuclear tests since three meetings between the two leaders including a brief one at the border of North and South Korea in June this year.