SEOUL, Korea, Republic Of - North Korean leader Kim Jong Un sent flowers and a message of condolence on Wednesday for the funeral of former South Korean first lady Lee Hee-ho, whose late husband held a historic summit with Kim's father in 2000.

Senior South Korean officials travelled to the border village of Panmunjom to receive the wreath and letter delivered by Kim's sister, Kim Yo Jong, a senior official of North Korea's ruling party, who called for the Koreas to honour Lee's legacy with further co-operation, a South Korean presidential official said.

Lee, the wife of late South Korean President Kim Dae-jung, died on Monday at 97. Her funeral proceedings are continuing through Friday.

The contact between the Korean officials at Panmunjom came at a delicate time in relations.

North Korea has significantly reduced its dialogue and engagement with South Korea since February, when a high-stakes nuclear summit between Kim Jong Un and President Donald Trump collapsed over disagreements on exchanging sanctions relief for disarmament. Negotiations between the U.S. and North Korea have also been at a standstill and Kim has declared that the Trump administration has until the end of the year to offer mutually acceptable terms for a deal to salvage the negotiations.

Kim Yo Jong, who is believed to be her brother's closest confidant,did not convey a separate message from him for South Korean President Moon Jae-in, said Chung Eui-yong, Moon's national security director who met her at Panmunjom. Chung said he didn't carry a message from Moon either.

“Today, the South and North focused on cherishing memories and mourning (Lee),” Chung said.

South Korea's Unification Ministry, which deals with inter-Korean affairs, released photos showing Kim Yo Jong smiling and talking with South Korean officials at a building on the northern side of Panmunjom and handling Chung a red folder that contained her brother's condolence letter.

In the letter, Kim Jong Un credited Lee and her husband with laying the foundation for the Koreas to take steps toward unification, peace and prosperity. The wreath sent by Kim was decorated with black ribbons with golden letters saying, “In memory of the late Lee Hee-ho” and “Kim Jong Un.”

Moon and Kim Jong Un met three times last year, issuing vague statements on denuclearization and peace and vowing to resume joint economic projects when possible, and voicing optimism that U.S.-led sanctions against North Korea could end and allow such co-operation.

Since the breakdown of the Trump-Kim meeting in Vietnam, North Korea has expressed its displeasure by resuming short-range missile tests and issuing belligerent statements toward American and South Korean officials. North Korea has also made nationalistic calls urging South Korea to break away from Washington and resume the joint economic projects held back by sanctions.

In a speech in Oslo, Norway, Moon, who is in the midst of a weeklong trip to northern Europe, downplayed the stalemate in talks, saying the countries need more time to “understand each other thoroughly.” Moon said he wants to meet Kim again soon, and that it would be “desirable” for their next summit to take place sometime before Trump visits South Korea in late June. But he said it was unclear whether the Koreas could prepare a summit that quickly.

“That's up to Chairman Kim,” said Moon, who also called for a quick resumption of summit talks between the U.S. and North Korea.

Experts say North Korea is trying to increase pressure on Washington and Seoul without actually causing the negotiations to collapse.

Kim Dae-jung won the Nobel Peace Prize in 2000 for his pro-democracy struggle and his rapprochement policies with North Korea, months after he met then-North Korean leader Kim Jong Il in Pyongyang in the first summit between the Koreas since their 1950-53 war.

North Korea sent a high-level delegation to the South after Kim Dae-jung died in 2009. Lee joined her husband's 2000 trip to Pyongyang for the summit and also visited the North Korean capital in 2011 after the death of Kim Jong Il, when she met and expressed her condolences to Kim Jong Un.