SEOUL, Sept. 1 -- South Korea on Monday reaffirmed its unwillingness to remove sanctions against the Democratic People's Republic of Korea (DPRK) amid growing speculation over the lifting to improve inter-Korean relations.

Unification Ministry spokesman Lim Byeong-cheol told a press briefing that there has been no change in South Korea's stance on the so-called May 24 measures, saying the sanctions should be basically maintained until the DPRK takes responsible steps.

The May 24 sanctions were imposed by South Korea in 2010 when the South Korean Navy corvette Cheonan sank in waters near the disputed western sea border in March that year, banning all inter- Korean exchange except for the joint factory park in the DPRK's border town of Kaesong.

Lim's comments came after some local media reported that Pyongyang already sent its message of expressing its apology to South Korea under the Lee Myung-bak administration during the inter-Korean closed-door meeting.

The spokesman said the DPRK's expression of apology was not " confirmed," and the apology will be effective only when it is expressed "formally."

Expectations spread among some local media that South Korea may ease or lift the May 24 sanctions to enhance ties between the two Koreas.

South Korea proposed to hold senior-level inter-Korean dialogue, to which the DPRK has not yet responded, to discuss issues, including reunion of families separated by the 1950-53 Korean War.

The spokesman said Seoul still hopes to hold the family reunion when conditions are met, urging Pyongyang to respond to the dialogue proposal as early as possible.