North Korea will hold parliamentary elections Sunday, a key political event likely to cement leader Kim Jong-un's grip on power and enhance national unity following the breakdown of the North's second summit with the United States.

North Koreans aged 17 or older will vote to elect new deputies for the country's rubber-stamp Supreme People's Assembly in the polls held every five years.

The voting, scheduled from 9 a.m. to 6 p.m., will replace those picked in the first parliamentary elections under the current leader in March 2014.

A total of 687 deputies were elected in the 2014 election, replacing 55 percent of the existing assembly members.

The voting is mandatory and generally considered a formality. The official voter turnout was tallied at 99-point-97 percent for the last election, with 100 percent voting for the approved candidates.

The election results are expected to be announced Monday or Tuesday.