Donald Trump deserves the death penalty for insulting North Korean leader Kim Jong Un, the country's state media has said.

Axar.az reports citing Skynews that, an editorial in the ruling party newspaper, Rodong Sinmun, called the US President a "hideous criminal" for urging the five Asian countries he visited last week to maximise pressure on North Korea to halt its growing nuclear programme.

The paper also called Mr Trump a "coward" for canceling a visit to the inter-Korean border.

"The worst crime for which he can never be pardoned is that he dared [to] malignantly hurt the dignity of the supreme leadership," the editorial said.

"He should know that he is just a hideous criminal sentenced to death by the Korean people."

Mr Trump refused to hold back on his usual criticism of Mr Kim during his 11-day trip to Asia.

While in Hanoi, towards the end of his trip, he taunted the North Korean leader over his height and weight.

He tweeted: "Why would Kim Jong Un insult me by calling me 'old', when I would NEVER call him 'short and fat'?"

The Rodong editorial attacked Mr Trump's failure to tour the demilitarised zone (DMZ) dividing North and South Korea, which has become a traditional stop-off for senior US officials visiting the south.

The US President's helicopter turned back after five minutes into the trip to the DMZ due to bad weather.

"It wasn't the weather. He was just too scared to face the glaring eyes of our troops," the editorial added.

On the same day the editorial came out, Mr Kim resumed his public outings after a two-month hiatus during heightened tensions with the US and its allies.

He visited a tractor factory which he boasted was made mainly with locally produced parts, in a bid to show sanctions could not hurt the country.

China, North Korea's sole ally, has now announced it will send a special envoy to the hermit nation this week.

President Xi Jinping's special envoy, Song Tao, will head to Pyongyang on Friday to discuss the Chinese Communist Party's congress, which took place last month.

Mr Trump had urged Mr Xi to use China's influence over the North to rein Mr Kim in, warning that "time is quickly running out".

On Sunday, Mr Trump said his Chinese counterpart stated "he is upping the sanctions against" North Korea, but China has not yet announced any new measures.

The Chinese president has said he wants to resolve the nuclear crisis through diplomatic means over fears a regime collapse could trigger a rush of refugees across its border.