By Ju-min Park and Christine Kim
SEOUL (Reuters) - South Korean President Park Geun-hye on Monday proposed amending the constitution to allow presidents to serve multiple terms or to establish a parliamentary system, saying the single-term presidency has served its purpose after nearly 30 years.
The South Korean presidency was limited to a single five-year term in the 1987 constitutional amendment that ended the country's military dictatorship.
South Korean presidents serving a single five-year term typically become lame ducks in the second half of their tenure, limiting their effectiveness.
Park herself would not be able to serve a second term.
"Through the single-term presidency, it is difficult to maintain policy continuance, see results of policy and engage in unified foreign policy," she said in an address to parliament at the start of annual budget deliberations.
Critics of the presidency believe a parliamentary system in which the executive branch centered on a prime minister and the cabinet would allow for more stable policymaking and ensure greater accountability.
Park, the first woman president of South Korea, is in the fourth year of a term which ends in February 2018.
A Realmeter poll released in June found 70 percent of South Koreans think the existing constitution should be revised and 40 percent say allowing a president to serve two four-year terms would be preferable.
Park asked parliament to form a special committee to discuss revising the constitution, calling for the change to be completed before her term ends.
In South Korea, the president or parliament can propose a constitutional amendment, which must be approved by a two-thirds majority in the single-chamber assembly and then by a majority in a national referendum in which more than half of eligible voters participate.
Under the current constitution, the sitting president is barred from serving again under any potential amendment.
"I've reached a conclusion that we can no longer delay discussing amending the constitution, which was also my campaign promise, to break down limits we face in the big picture for the Republic of Korea's sustainable development," Park said.
Despite broad public consensus for constitutional reform, it is not clear how debate will play out, with political power split between a powerful presidency and a fractious parliament.
Park's proposal was welcomed by her Saenuri Party but drew suspicion from rival parties which saw it as a move to divert attention from an influence scandal involving old acquaintances and to keep herself relevant as her presidency winds down.
Park's father, Park Chung-hee, who took power in a coup in 1961 and served as leader until he was assassinated by his spy chief in 1979, forced through a constitutional amendment in 1972 to extend his presidency.
U.N. Secretary-General Ban Ki-moon said on Friday he will return to South Korea in January after heading the world body for a decade to consider what role he can play amid a push for him to run for president.
(Editing by Jack Kim and Nick Macfie)