The South Korean government said Friday that it is difficult to single out who led North Korea's deadly sinking of the Cheonan warship in 2010.

The explanation came amid controversy surrounding a planned visit by a senior Pyongyang official who is widely suspected of masterminding the attack.

Unification Ministry Spokesman Baik Tae-hyun said it is clear that North Korea is to blame for the warship sinking and that Kim was leading North Korea's reconnaissance bureau at that time.

But he added that it is also a fact that there is a limitation in pinpointing who was responsible for the incident.

Kim Yong-chol, the head of the ruling party’s United Front Department, will come to the South for a three-day visit on Sunday as the head of the North's high-level delegation to PyeongChang Winter Olympics closing ceremony.

Conservatives and families of the 46 victims are strongly opposing his visit. 

Baik said the government is well aware of concerns about the government's approval of the visiting delegation led by Kim but called for public understanding of Seoul's decision, which he said is aimed at improving inter-Korean ties and eventual peace on the Korean Peninsula.