Prime Minister Ryutaro Hashimoto announced Monday that he will resign to take responsibility for the massive defeat of the Liberal Democratic Party in Sunday's Upper House election.

In the wake of the widely expected announcement, the LDP began a full-scale process for choosing Hashimoto's successor as party president and prime minister.

The LDP is scheduled to hold a general assembly of LDP Diet members on July 21 to select a new party president, who will most likely be elected prime minister at an extraordinary Diet session to be convened at the end of the month.