The six North Korean officials arrived in South Korea on Friday to mourn late former President Kim Dae-jung, a champion of inter-Korean dialogue who died Tuesday. It is the first time the North has sent a delegation to mourn a South Korean leader.
Any meeting with Lee would be significant because relations between Pyongyang and Seoul have been tense since the conservative, pro-American former businessman took office in February 2008.
He vowed to take a tougher line on North Korea and tied aid to the impoverished nation to progress on its denuclearization. North Korean media regularly deride him as a "traitor."
An official dealing with inter-Korean affairs in Lee's office said officials were considering the request for a meeting but had not yet decided. He spoke on condition of anonymity because he was not authorized to speak to the media.
South Korea's Yonhap news agency, citing a source it did not identify, said the delegation was carrying a letter from North Korean strongman Kim Jong Il.
The six North Koreans were originally scheduled to return home Saturday afternoon. South Korea's YTN television reported that they would stay another day and that Lee had no plan to meet the officials Saturday.
North Korean spy chief Kim Yang Gon, who also handles inter-Korean affairs, held an 80-minute meeting with South Korean Unification Minister Hyun In-taek earlier in the day, the first such top-level meeting in almost two years. South Korea did not immediately release details of the meeting.
The two planned to have dinner Saturday and would likely discuss a possible meeting with the president, the official in the presidential office said.
On Friday, the North Korean officials offered a floral wreath to the late president, who was beloved on both sides of the border for his pursuit of closer ties between the divided states. His funeral is Sunday.
Kim Yong-hyun, a professor at Seoul's Dongguk University, said he expected Lee to meet with the delegation Sunday. He said Lee is likely to be reluctant to show eagerness to meet the North Koreans since it could invite a backlash from conservatives who oppose any indication of softness toward Pyongyang.
About 100 demonstrators chanted "topple the Kim Jong Il dictatorship" Saturday near the hotel where the North Korean officials were staying and ripped apart paper North Korean flags.
There was a minor scuffle between the activists and police.