SEOUL - South Korean President Moon Jae-in on Wednesday dismissed the idea that nuclear negotiations between Pyongyang and Washington had stalemated but stressed patience was needed to bridge a 70-year "sea of mistrust".

In written answers to questions submitted by leading media, Moon - who brokered talks between US President Donald Trump and North Korean leader Kim Jong Un last year - also urged Pyongyang to resume the dialogue to show its desire to denuclearize.

Moon is set to host the US leader this weekend as he tries to rekindle nuclear talks that have stalled since the collapse of a second summit between Trump and Kim in Hanoi in February.

The pair failed to reach an agreement on sanctions relief and what the North might be willing to give up in return, and Pyongyang has since not responded to calls for dialogue, maintaining only minimal contact.

"There is no reason to regard the current situation as a stalemate in the peace process on the peninsula just because the pace has remained slow," Moon said.

Trump and Kim's willingness to engage in dialogue had "never faded", he added in the interview with editors of major news agencies including AFP, noting a recent exchange of letters between them.

On Sunday, the North's state media reported that Kim received a personal message "of excellent content" from the US president, just days after Trump said the North Korean leader had sent him a "beautiful letter".

Trump has insisted he was in "no rush" for a third meeting with Kim, but Moon said Wednesday that "behind-the-scenes talks" were going on between Pyongyang and Washington for another summit.

Despite the top-tier correspondence, US officials say privately the North has been sitting on their offer for working-level talks and the South Korean unification minister recently admitted that the talks process was at a standstill. -AFP