There had been speculation that Pyongyang might do so Friday, when Ri Yong Ho met Swedish Prime Minister Stefan Lofven and Foreign Minister Margot Wallstrom, but afterwards Swedish officials said the talks would be extended into Saturday.
The ministry said ahead of the North Korean diplomat's visit that his meetings with Wallstrom would focus on "Sweden's consular responsibilities as a protecting power for the United States, Canada and Australia", but also would address the security situation on the Korean Peninsula.
There was no official word from North Korea since the invitation was delivered via South Korean officials in Washington.
"If we can use our contacts in the best way, we will do so", Wallstrom said, noting the situation on the Korean peninsula was "of interest to us all".
The official confirmed that Pompeo has taken the lead on planning because after the departure of Joe Yun, the State Department's point person on North Korea, intelligence agencies are the main source of expertise on the country.
While some experts have questioned the sincerity of North Korea's outreach and expressed doubt the summit will materialise, Mr Trump has projected confidence.
Meanwhile, Japanese broadcaster TBS said Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-in discussed North Korea in a telephone call on Friday.
Mr. Trump embraced Mr. Kim's reported gesture last week and officials have predicted a direct Trump-Kim meeting could occur - potentially in the neutral location of Sweden - as early last May.
The US president has agreed to meet the North Korean leader by May.
Sweden 'prepared to facilitate' Donald Trump's meeting with Kim Jong Un
Mr Ri will meet Swedish foreign minister Margot Wallstrom at an undisclosed location on Thursday or Friday, the Swedish Foreign Ministry said.
The DPRK launched several missile and nuclear tests a year ago, while the United States and South Korea have exerted the "maximum pressure" against the DPRK and held military drills around the Korean Peninsula, further escalating tensions.
The meeting between the two countries is in the works after a surprise about-turn by Kim Jong Un in offering talks with Donald Trump.
Sweden has longstanding ties with North Korea.
But no specific time or venue has been set and North Korea has yet to confirm it even made the offer to meet.
Swedish Prime Minister Stefan Lofven, speaking at a press conference with German Chancellor Angela Merkel in Berlin, did not answer directly whether his country had USA support to organize talks with North Korea.
Wallstrom's press secretary, Pezhman Fivrin, said the talks, which had been due to end late on Friday, would continue on Saturday.
On Thursday, the head of the US Pacific Command, Admiral Harry Harris, cautioned the United States could not be overly optimistic about the outcome of any summit between Trump and Kim and must go into it with "eyes wide open". She said that "we value this opportunity to arrange a meeting", though she didn't specify what she meant.
A report on Friday by intelligence analysts at Jane's by IHS Markit said satellite imagery from 25 February showed gas emissions at the North's experimental light water reactor, suggesting preliminary testing had likely begun.
Kono asked Mattis to cooperate in comprehensively resolving the issue of North Korea's nuclear and missile development and its abductions of Japanese citizens.