A Gallup Korea opinion survey last month found 54 per cent supporting constitutional revision to fix the presidential system and 30 per cent saying that is unnecessary.
Yoon said on Sunday that although he had stepped down, he would “always stand by” his supporters, who fought for “freedom and defending sovereignty”.
Acting President Han Duck-soo and the election commission are considering Jun 3 for the election date, the commission has said.
The constitution was last revised in 1987 to introduce direct presidential elections and a single, five-year term.
In recent years, presidential candidates from across the political spectrum have supported revisions including giving presidents two four-year terms, but there have been few concrete steps after new leaders were chosen.
Yoon’s ruling People Power Party is studying possible amendments, and its presidential hopefuls have mentioned barring presidents from seeking more than two four-year terms.
The leading candidate to replace Yoon, main opposition Democratic Party leader Lee Jae-myung, has also spoken of that idea.
