The influential sister of North Korean leader Kim Jong Un said Tuesday that Washington had "wrong" expectations for dialogue with Pyongyang and was facing "disappointment," state media reported.

The White House promised a "practical, calibrated approach" -- including diplomatic efforts -- in a recent review of its strategy to persuade the impoverished North to give up its nuclear and missile programme.

Sung Kim, the top US diplomat in charge of North Korea negotiations, underlined the message Monday during a five-day visit to Seoul, where he said Washington was ready to meet with Pyongyang "anywhere, anytime, without preconditions".

But Kim Yo Jong -- a key adviser to her brother -- appeared to dismiss prospects for an early resumption of negotiations, saying the US seemed to be seeking "comfort for itself".

Washington harbours expectations "the wrong way", which would "plunge them into a greater disappointment", she added in the statement reported by Pyongyang's official KCNA news agency.

Since US President Joe Biden's election, the two countries have adopted a wait-and-see attitude to relations following the diplomatic roller-coaster ride under Donald Trump that produced three historic summits but no agreement on dismantling the North's nuclear arsenal.

Kim Yo Jong is a key adviser to her brother
Kim Yo Jong is a key adviser to her brother POOL / JORGE SILVA

Kim Jong Un said last week that Pyongyang needed to prepare for both "dialogue and confrontation" with Washington -- but with a particular emphasis on the latter.

The North at the weekend admitted it was tackling a food crisis, sounding the alarm in a country with a moribund agricultural sector that has long struggled to feed itself.

It is now under self-imposed isolation to protect itself against the coronavirus pandemic, and as a result trade with Beijing -- its economic lifeline -- has slowed to a trickle while all international aid work faces tight restrictions.

Kim Yo Jong's remarks "have not changed our view on diplomacy", US State Department spokesman Ned Price told reporters.

"We remain prepared to engage in... negotiations with the DPRK to deal with the challenge of its nuclear programme."

Price said the US hoped North Korea would "respond positively" to the US offer to meet.

"Again, our policy is not aimed at hostility. It is aimed at solutions. And it is ultimately about achieving the complete denuclearization of the Korean Peninsula," the spokesman added.