The widow of late South Korean president Kim Dae-Jung will make a rare trip to North Korea on Wednesday, raising cautious hopes of a thaw in cross-border tensions despite Seoul playing down the trip as a purely personal affair.

The visit by Lee Hee-Ho is ostensibly humanitarian in nature, with the 93-year-old planning to tour a children's hospital, a maternity home and an orphanage in Pyongyang.

But all eyes are on whether she will meet with North Korean leader Kim Jong-Un, who has yet to receive any South Korean citizen since formally assuming power more than three years ago.

The two have already met once -- when Lee visited to pay her respects following the death of Kim Jong-Un's father and former leader Kim Jong-Il in December 2011.

Her late husband is best known for his "sunshine policy" of engagement with the North that led to a historic summit with Kim Jong-Il in 2000.

The policy -- which helped Kim Dae-Jung win a Nobel Peace Prize in 2000 -- was largely abandoned when a conservative administration took power in Seoul in 2008 and cross-border relations soured.

- Simmering tensions -

A series of nuclear and missile tests, as well as occasional military clashes along the border, have kept tensions on a high simmer.

Pyongyang has repeatedly rejected calls for talks with the South, citing Seoul's refusal to cancel annual joint military drills with the US.

But Kim Dae-Jung still commands some level of respect from Pyongyang, and the North's pugnacious state media has refrained from subjecting him to the same personal, vitriolic attacks it reserves for most South Korean presidents, past and present.

And Lee's visit -- personally approved by Kim Jong-Un -- may offer a window for resuming a dialogue over relatively non-political issues, said Jeung Young-Tae, an analyst at the Seoul-based Korea Institute for National Unification.  

Those might include long-stalled talks to hold another family reunion for those separated during the 1950-53 Korean War, as well as the resumption of tours to a scenic mountain resort in the North, he said

And there is "some possibility" that Lee will be able to meet with Kim Jong-Un, who also gave the green light for Lee to fly directly from the South to the North.

Direct flights between the two countries, who remain technically at war, are extremely rare.

- A 'symbolic figure' -

"North Korea has traditionally tried to lend political weight to liberal political figures who are friendly to them, and Lee Hee-Ho is such a symbolic figure," Jeung told AFP.

Seoul has repeatedly stressed that Lee's visit has no official trappings of any kind.

"Lee's trip is a significant event but we are not planning to send any official messages through her," Park Soo-Jin, spokeswoman for the Unification Ministry that handles cross-border affairs, said Monday.

Lee will be accompanied by a 18-member entourage including former Seoul officials, humanitarian workers and liberal ideologues, but no sitting government official.

The visit comes just ahead of the 70th anniversary of the August 15, 1945 liberation of the pre-division Korean peninsula from Japanese colonial rule.

At the start of the year, there had been hopes that the anniversary could serve as an icebreaker for a resumption of dialogue, but the two sides have been unable to agree on any joint celebratory event.