TOKYO - The Japanese parliament on Wednesday passed a revised law to lower the country's voting age from 20 to 18, marking the biggest reform of the election system in 70 years.

The House of Councillors in the parliament, or the upper house, passed the so-called revised public office election law, which was approved by the lower house on June 4. Japan last lowered the voting age from 25 to 20 in 1945.

Under the revised law, about 2.4 million people aged 18 and 19 will join the electorate. The law will be promulgated in about a week and take effect in one year, according to Japan's Kyodo News.

The minimum voting age for national referendums on constitutional amendments was set to be lowered from 20 to 18 in 2018 under a revision to the national referendum law enacted last year.

Analysts said that to lower the voting age could help the young generation to express their thoughts in current politics, but it is necessary to raise their involvement in politics.