North Korean leader Kim Jong-un hosted a military meeting to discuss new policies to bolster the country's nuclear capabilities amid stalled denuclearisation talks with the United States, state media KCNA said.

The meeting of the ruling Workers' Party's powerful Central Military Commission marked Mr Kim's first public appearance in three weeks.

He made an unusually small number of outings in the past two months amid coronavirus concerns.

North Korea has imposed strict anti-coronavirus measures although it says it has no confirmed cases.

This follows intense speculation about Mr Kim's health last month after he missed a key anniversary.

US-led negotiations aimed at dismantling North Korea's nuclear and missile programmes have made little progress since late last year, especially after a global battle on the coronavirus began.

The meeting discussed measures to bolster armed forces and "reliably contain the persistent big or small military threats from the hostile forces," KCNA said.

"Set forth at the meeting were new policies for further increasing the nuclear war deterrence of the country and putting the strategic armed forces on a high alert operation," it said.

"Taken at the meeting were crucial measures for considerably increasing the fire power strike ability of the artillery pieces."

The Chinese government's top diplomat, Wang Yi, expressed hope that the US and North Korea could resume meaningful dialogue as soon as possible.

"We hope that all parties, including the United States,would seriously consider it, and not squander away the hard-earned results of (previous) engagement," Mr Wang told a media briefing in Beijing.