The South Korean presidential office has welcomed the planned Washington-Pyongyang summit as the time and venue were announced during the State of the Union address in Washington.

Presidential spokesman Kim Eui-kyum told a briefing Wednesday that Seoul hopes "specific and substantive results" would emerge from the second summit at the end of this month.

While referring to the history of U.S.-Vietnam relations that turned hostile to friendly, the spokesman said Seoul expects the venue would serve as the best backdrop to write a new history for the U.S. and North Korea. 

The spokesman refused to discuss in which Vietnamese city the summit will be held, noting that Washington and Pyongyang are soon expected to make further announcements. 

He also told reporters that it is unlikely President Moon Jae-in would fly to Vietnam during the summit amid speculations that the two Koreas, the U.S. and China might declare an official end to the Korean War.