Choe Son Hui, North Korea's foreign ministry director general for USA affairs, made the announcement to journalists in Beijing, a South Korean news agency reported.
Kim Jong Un was the target of a US-South Korean assassination plot, North Korea claims.
When asked if the North would be open to talks with South Korea's newly-elected president, Moon Jae-in, Choe replied, "We'll see".
Choe Son-hui, a foreign ministry official for the reclusive country, has said bilateral talks between Pyongyang and Washington would be considered.
The comments from Pyongyang have come after months of heightened tensions between USA and North Korea over the North's nuclear programme ambitions.
Trump's administration since then has said that Pyongyang must agree to abandon its nuclear and missile programme before relations between the countries can improve.More news: White House refuses to say if conversations are being taped
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The office said: "We urge the relevant authorities to immediately detect and arrest and hand over to the DPRK the masterminds of the disgusting state-sponsored crime, accomplices and their followers".
Hwang Jaeho, an global studies professor at Hankuk University of Foreign Studies in Seoul, said the timing for the belt and road summit was significant, with signs that tensions were already easing following the inauguration of new elected South Korean president Moon Jae-in.
Trump didn't make clear what those circumstances would be, naturally, but did appear to reject the need for talks in the near term, bragging that he's handling North Korea "very well, very firmly" without diplomacy.
The North is technically still at war with the South and has no diplomatic relations with the U.S., but China is its sole major ally.
The new South Korean president faces the daunting task of finding a way to restore relations without upsetting worldwide partners such as the USA, given Pyongyang's self-description as a nuclear weapon state.
North Korea's Vice Foreign Minister Han Song Ryol speaks during a meeting at the People's Palace of Culture in Pyongyang, on May 11, 2017.
North Korea said US and South Korean agents bribed and coerced a North Korean man into joining the plot which was foiled by its state.